The Kingdom of Darkness is the fortieth issue of the Winx Club Comic Series.
While out on a hike, the Winx, the Specialists and the Pixies encounter a sudden storm that opens up a portal into another realm. Monsters exit the portal and kidnap Stella due to her light magic, and it is now up to the group to rescue their friend alongside a kingdom plunged into darkness.
The Winx, the pixies and the Specialists are hiking up some mountains. Stella complains, doubting that they will not be able to climb up the mountain, until Bloom advises her to be more considerate since the boys have been wanting to go on this hike for a while now. She then adds that the hike will be more fun with the pixies by their side, to which Lockette agrees and offers to share some of the blueberry cakes she brought. Amore offers to share some snacks with Stella to help her gain more energy but Stella does not want an, as she is struggling to breathe already. Amore tells her to take deeper breaths as getting air on such a beautiful day will help her become more beautiful, but Stella notices that dark clouds are starting to come together. Strong winds begin to pick up, which begins to worry Flora, but Brandon claims that there is some shelter nearby, so they will not need to worry so much. However, as Brandon tries to lead the group to somewhere safe, the winds get stronger as lightning begins striking areas near them. Sky realizes that this storm cannot be a natural one as storms as big as this one do not just happen that quickly, causing Bloom to suspect that there may be witchcraft behind it.
More and more lightning begins to strike at the group until they are able to find some rocks to hide under. As they take shelter, the lightning strikes at a nearby cliffside. Sky asks how such a large storm where only lightning occurs is possible, until Tecna comments on how the lightning is not striking at random, but is carving something into the cliffside next to them. The lightning carves out a gate to another world, which opens and releases Gloom Monsters. As the group tries to figure out where the Gloom Monsters are from and who could have released them, Stella proposes that they fight the monsters back or else Magix will be in danger again. Sky tries to get her back into the shelter but Stella runs out to confront the monsters. One of the Gloom Monsters tries to attack her but she manages to dodge and goes into her Enchantix to fight back. As she takes out the Solaria Sceptre, the rest of the Winx come out of hiding to aid Stella in battle. The girls begin to fight the monsters as Brandon decides to join the fight as well, believing that they cannot sit back and let the girls fight alone just because they do not have their weapons with them. He swings a large stick at a Gloom Monster but nothing happens. Bloom attacks two of the monsters with a spell and they dissolve into fog, however, they quickly reform. As they try to figure out what to so, Bloom and Musa notice that the monsters seem attracted to Stella and they watch as she tries to fight them all back.
Soon enough, the monsters grab Stella and start heading back into the doorway. Brandon, Bloom, Musa, Flora, Riven and Aisha chase after the Gloom Monsters in an attempt to free Stella and the doorway closes behind them. Just as Tecna, Sky, Timmy and Helia try to come up with a way to force the doorway open, the lightning storm returns and multiple lightning strikes begin to tear down the doorway. The doorway ends up completely destroyed, leaving the remaining group members powerless to help their friends. Lockette lets them know that they are all here with them except for Amore, who also went into the doorway to free Stella. Sky proposes that they return to Red Fountain in order to get some help in figuring out which realm their friends are now trapped in.
Meanwhile, the Gloom Monsters approach a cart full of barrels. They open one of the barrels, stuff Stella inside it and head off. Brandon's group, however, is not too far behind the Gloom Monsters. Lost in a dark and dreary realm, the group tries to figure out where they are. Brandon suspects that they are in another realm but it is hard to tell because there are no lights, stars or even a sun to give light to it, however, through the dense fog, Musa manages to catch a glimpse of what looks like a road. The group follows the road and comes across a small village. Brandon knocks on one of the cottage doors to see if the village truly is abandoned, and a woman opens the door, urging them to come inside before anyone sees them. The woman claims that if they are to get caught then they will get in big trouble.
With everyone inside, the woman makes sure that the door is closed shut and tells her husband to turn the lamp back on. Bloom asks if they are scared of the Gloom Monsters finding them, to which the woman explains that them alongside the king's soldiers serve under the Lord of Darkness and they go prowling across the land for any light sources. Bloom asks who this Lord of Darkness is, to which the man reveals that he is their king and he has an evil wizard as his sole advisor. He further explains that the evil wizard, Zaltor, approached the king a year ago, claiming that he had a cure for his dwindling sight. The cure seemed to work at first until the king gradually became more evil and intolerant under Zaltor's influence and, under the pretenses of not allowing his enemies see how serious his illness is, Zaltor coerced the king to have all lights extinguished. In reality, Zaltor needed the darkness in order to create his Gloom Monsters. Brandon asks if this means that Zaltor rules over the kingdom now, to which the man reveals that many people were either sent off to fight in a war that may not even be real or were killed after being accused of treason. There are also some people within the kingdom who support Zaltor's reign. The man then reveals that, without light, the plants cannot grow and that Zaltor is planning to have them all die from hunger so that he will not face any resistance. Bloom cannot understand why Zaltor would want to rule over an empty kingdom if he were to have everyone killed, but the man insists that Zaltor is only interested in all of the darkness since his powers will grow stronger and, once the kingdom has become nothing, Zaltor will lead his army of Gloom Monsters into another kingdom in order to conquer it as well. Musa then realizes that the lightning storm from earlier must have been caused by Zaltor, meaning that he will move on to conquer Magix once he is done with this kingdom. Bloom and Brandon add in that he must have had his monsters kidnap Stella since she is the Fairy of the Shining Sun, meaning that she would be the most dangerous enemy for him. Riven then asks the couple where they could find their friend, and the woman tells them that she would be found in the Black Castle, but they would be better off forgetting about Stella because the castle is such a labyrinth.
Suddenly, there are loud knocks at the door. Two of the king's men have brought two Gloom Monsters with them in order to conduct an inspection on the couple's cottage.
The woman begins to panic, suspecting that the group must have been spotted earlier, and the man shows them to his cellar door, explaining that it will lead them into a secret passage under the village. Since the couple will get into big trouble for having Brandon's group with them, they agree to escape with them. Just then, one of the king's men orders the Gloom Monsters to break the front door down.
Luckily, the group and the couple are already within the secret tunnels. They come across another cellar door, which they all exit from, and the woman tells them that they have managed to make it just beyond the vegetable patch near the forest. Before they try to escape farther, Brandon tells the woman that he needs to find Stella before they escape. He then comes up with the idea to let himself be captured by the Gloom Monsters, believing that they will take him to the same place Stella is being held. If the rest of his group were to follow the monsters in secret, then they would also be able to know where Stella is. Amore insists on going with Brandon and she hides in his shirt-pocket. Bloom asks if he is absolutely sure that he would want to do this, to which Brandon tells her that while it may be risky, there is no other option, and he trusts that Bloom and the rest of them will be able to rescue Stella if he cannot. The man starts to hear noises and suspects that the king's men must have discovered their secret tunnel. Brandon runs back for the cottage in order to distract the monsters as his friends and the couple hide safely in the woods.
Soon enough, the king's men have made it out ot the secret passage and spot Brandon just outside. As they give chase, Bloom and the others are hiding behind some trees nearby.
Brandon tries to fight off the Gloom Monsters sent after him, but he is quickly pinned down and apprehended. One of the king's men reminds the other that their new prisoner may have escaped with more people, due to the multiple footprints they found within the secret passage, however, the other king's man claims that they will be able to make Brandon tell them who his friends are once they take him back to the castle. The king's men have their Gloom Monsters put Brandon onto a barred cart and take him to the Black Castle. Unbeknownst to them, his friends are following them closely behind.
From a nearby boulder just beyond the castle's moat, Riven and the girls notice that the Black Castle is heavily guarded. Riven runs off, suggesting that they look for any weak spots in the castle's defenses, and the girls follow.
Inside, the king's men force Brandon into a cell for him to rot in until Zaltor comes up with fitting punishment. Once the king's men are gone, Brandon lets Amore know that it is safe for her to come out. Amore flies out of Brandon's shirt-pocket and asks if he was able to see Stella anywhere, but Brandon was unable to see her anywhere. Before Amore flies off to look for Stella, Brandon tells her to bring him back the cell keys and then tell the others about Stella's whereabouts after she is found. Amore tells Brandon that she can handle it and flies off. Lucky for her, all of the king's men are nowhere to be seen.
Meanwhile, at Red Fountain, Sky, Tecna, Helia and Timmy have gotten the three headmasters together and told them that the rest of their friends have become trapped within another realm. As they try to come up with a plan, Sky mentions that the door was destroyed and asks how they will be able to enter the realm. Saladin explains that they need to move fast if the other realm is planning to invade and suspects that the door they saw earlier was merely a wizard from the other realm testing his abilities. He, Griffin and Faragonda suspect that there must be a more powerful door somewhere close by that the wizard had prepared for the invasion. Codatorta tells the boys that they will organize multiple search teams and that the first team to find the door must destroy it. Sky, Timmy, Helia and Tecna then leave Saladin's office in order to prepare.
Back in the other realm, Amore flies passed one of the king's men who is sleeping on the job. She then picks up Stella's perfume and follows the scent into another cell, which is full of barrels. She tries to open one of the barrels but it is too heavy, so she sprinkles a bit of pixie dust that makes the lids lighter. When she opens up the barrel, she finds all of the stars from the night sky inside and, when she opens another, she finds a million fireflies inside. Amore then checks another barrel and finds Stella trapped inside!
Amore wonders why Stella cannot just fly out from the barrel, but Stella reveals that a powerful spell has been casted on the barrels which is preventing her from escaping. She tells Amore that the only way for her to escape his for her to break the barrel from the outside and Amore assures Stella that she will not have to worry, as she will find a way to set her free. Amore puts the lid back on the barrel and flies out of the cell. Just as she is heading back to meet up with Brandon in his cell, Amore catches three of the king's men talking about how they need to change guards in the Crystal Room, as that is where Zaltor keeps the source of all his accumulated black magic: his Black Crystal.
Amore follows the king's men into the Crystal Room, where Zaltor is powering it up. He claims that once his Black Crystal reaches its maximum, then they will prepare to invade the next realm. Amore flies off before she is caught and plans to tell Brandon of what she has just learned.
Amore flies passed the sleeping king's man again and steals the cell keys that are hanging on a nail protruding from the wall just next to his head. However, due to using up all of her pixie dust, Amore cannot make the keys easier to carry and struggles to get them all the way back to Brandon's cell.
Eventually, Amore makes it back to Brandon's cell with the cell keys. Brandon asks if she was able to find Stella, to which Amore confirms and tells him that she cannot escape from the barrel she was put in due to a powerful magical force. She then reveals that in order to break the magical force, they need to destroy a large crystal that is located in a sparkling room at the top of the castle. Brandon commends Amore for finding out everything they needed to know and then sends her out through a small barred window to find Riven and the girls to let them know, too.
At the same time, Specialist shuttles are flying through the skies, looking for the larger, more powerful door to the other realm. The three shuttles break formation, with Sky's shuttle flying straight ahead. He asks Timmy how they will be able to find the doorway, but Timmy is not exactly sure himself. He remembers the dark clouds from the lightning storm and suspects that sudden dark clouds coming together could be a clue. Soon enough, Sky spots some dark clouds spewing from the side of a mountain. Timmy pilots the shuttle towards those dark clouds, and the group comes face to face with a volcano that was never there before! Timmy mentions that it may just look like an erupting volcano from afar, and Sky soon realizes that it is the doorway they have been looking for. Timmy then calls the other shuttles via radio to regroup towards the east and pilots the shuttle into the portal as soon as the other groups report that they have received his orders.
Meanwhile, in the other realm, Amore finds Riven and the girls and tells them that she has found Stella. She then relays the rest of the information she gathered while inside and the Winx transform once they have come up with a plan. As they are flying towards the highest point of the Black Castle, Riven advises Musa to be careful and she does the same.
Amore leads the girls towards the Crystal Room, which catches the attention of the king's men stationed to guard the room. One of them frantically tries to sound the alarms but, before they know it, the Winx crash into the Crystal Room. They concentrate their magic on the Black Crystal in an attempt to destroy it, however, more of the king's men and Zaltor's Gloom Monsters storm into the room to defend it. In order to defend themselves, the girls have to use their powers to keep the Gloom Monster from attacking them. Musa claims that there are too many monsters in the way of the crystal and Bloom tells her that they cannot give up, even if they need the boys' help.
As the Winx continue fighting, a Specialist shuttle is heading for the castle. They see Riven who is signaling for them to land just outside of the Black Castle and the shuttle lands. As Riven is climbing on board, Sky asks him where the girls are, where Riven reveals that they are fighting at the top room of the castle.
Back inside the Crystal Room, the girls are becoming overwhelmed with the amount of Gloom Monsters coming in. The Black Crystal is also absorbing their powers so they can barely manage to fight back, however, before they are captured by the monsters, a spray of lasers fire into the Crystal Room. The Winx find cover as they realize that the Specialists came to rescue them. As the boys keep up with barrage of lasers, one of the lasers lands a direct hit on the Black Crystal, shattering it completely! More shuttles arrive and fire around the Black Castle, knocking down Gloom Monsters as the castle crumbles below them.
From his cell, Brandon hears the laser fire and realizes that the invading forces must be Red Fountain shuttles. With the cell keys Amore retrieved earlier, Brandon frees himself and makes his way outside in order to join the fight. A king's man tries to stop him but Brandon punches him out of the way. Eventually, Brandon makes it to the cell Amore claims to have found Stella in and starts looking in each of the barrels. In the second barrel he looks in, Brandon finds Stella and frees her. With the spell now broken, Stella uses her magic to bring sunlight back into the realm.
From outside, the sun is shining as bright as ever and its light causes the Gloom Monsters to dissipate. The Winx and Specialists celebrate over beating the darkness.
Immediately after the battle is over, the Winx treat the sick king with a potion to cure his illness and any lingering influence Zaltor may still have over him. The king is ecstatic about his sight returning to him and Bloom explains that he was not really sick but was actually under Zaltor's influence. The king thanks the Winx for saving him and his kingdom, until Musa tells Bloom that Zaltor must have escaped because they cannot find him anywhere. Bloom then tells Musa and the girls that they can never fully eradicate the universe of all of its evils and she fears that they may end up facing him again.
- Dragon Power - Used by Bloom to attack two of the Gloom Monsters.
- "May sunlight return everywhere!" - Used by Stella to help bring light back to the other realm.
- Stella is missing her gloves despite being in her Enchantix form on the issue's cover.
- Throughout the issue, whenever Stella goes into her Enchantix form, her gloves are a bluish-white instead of being pink.
- On page 9, as most of the Winx, Brandon, Riven and Amore chase the Gloom Monsters in an attempt to free Stella from their clutches, Flora, Aisha and Musa's Enchantix forms hold some minor errors.
- Instead of wearing a pink floral dress, Flora is wearing a rainbow top and a light pink skirt.
- Aisha's Enchantix wings are missing their yellowish-green borders, making them look purple.
- Musa's hair retains its usual dark blue color instead of gaining a more purplish color and her Enchantix wings have purple borders instead of yellow ones.
- Throughout the issue, the borders of Tecna's Enchantix wings switch between yellowish-green and purple.
- Her top is also a light blue color instead of being purple and, even though her hair changes in appearance, it remains short instead of becoming shoulder-length.
- Throughout the issue, the scarf that Stella wears has a tendency to switch from being green with pink stripes to pink with green stripes.
- On page 15, as Bloom, Brandon, Aisha, Flora, Musa and Riven have been pulled into the couple's cottage to hide, Lockette appears on Bloom's shoulder in two panels, despite the fact that the only pixie that followed Stella into the other realm was Amore.
- On page 35, when Timmy, Sky, Tecna and Helia find the random volcano, Sky's pin is yellow instead of blue.
- On page 36, when the Winx go into their Enchantix forms, there are a lot of errors aside from the one's already mentioned.
- The insides of Aisha's Enchantix wings are more of a reddish color rather than being purple, her sandals have red crystals in them, her top is blue with a yellow pattern instead of being green and pink with a blue pattern, and her skirt is mostly pink with yellow floral frills instead of being blue with a pink and green stripe ending in green floral frills.
- Flora's gloves are orange instead of pink, the borders of her Enchantix wings are purple instead of pink, her dress is mostly purple, and her sandals have blue crystals covering her toes.
- Musa also have blue crystals covering her toes on her sandals.
- Bloom's layered dress is mostly pink instead of mostly being different shades of blue, and the insides of her Enchantix wings are mostly pink instead of being clear.
- The Winx
- The Specialists
- Alfea Staff
- Cloud Tower Staff
- Red Fountain Staff