Author: Melissa De La Cruz
Length: 320 Pages
Summary: contains spoilers
Mal, Evie, Jay and Carlos receive messages to return to the isle by the new moon and Mal's is signed "M." They immediately assume their parents are behind the letters and that is all but confirmed when Evie can't see their parents in her magic mirror except lizard Malificent.
Meanwhile King Ben is dealing with an issue of his own. Camelot seems to have a monster stalking it and Merlin has come to seek permission to use magic to catch it. When Ben ventures to Camelot and meets with the Knights of the Round Table it is confirmed that no one has actually seen the monster. Ben and the knights go on a camping expedition to the last known location and are stunned to find the monster is a purple dragon. Ben rushes back to meet with the council and come up with a game plan, he thinks it could possible be Malificent, but how is she getting out of her glass dome?
Carlos starts tracing the email he received asking him to return to the island and stumbles upon the evil Internet. There is a message board dedicated to the Anti-Heros with a picture of the four with their faces crossed out. They come up with a plan to return to the Isle and crash the anti-hero meeting and confront their parents. As they are leaving for the Isle they meet up with Ben who approves of their plan and tells them about the purple dragon.
Once back on the Isle they start looking for their parents but no one has seen them. They run into some old acquaintances who appear to be up to something. They go to the location of the Anti-heros meeting which is held in the basement of the Evil Queen's castle. They are surprised to find Yen Sid (one of the teachers from Dragon Hall) teaching a select group how to be good. The Anti-heros meeting is a group dedicated to emulating the goodness that the first four to leave the island found since good is more powerful than evil. They ask the professor where their parents are, but while he isn't certain he thinks they may be looking for the tunnel that connects the Isle of the Lost to Auradon. He explains that his class has been studying and trying to map the tunnels because they are protected by magic and unless the magic is released it will continue to build and could destroy the island and Auradon. Mal, Evie, Jay and Carlos are the only ones that can get the medallions and stop the magic, if their parents get to them first they will have their evil powers restored.
Meanwhile in Auradon Charmington is being stalked by a large purple snake. Ben ventures out to try to find a scale of the creature so the fairies can analyze it and tell him if it is definitely Malificent. He manages to find a scale at a farm where the snake had slithered into a chicken coop, he takes the scale to Neverland to the fairies. After the fairies examine the scale they can not tell him if it was from Malificent or not but they do tell him that there was a mine the dwarfs started excavating years ago that also contained scales. The mine was shut down after finding the scales but the scales found there are a match for the scale Ben found. Ben goes to get Merlin and comments he will let him bring his wand and heads for the mine tunnel.
Back on the island Mad Maddie and some other Isle residents throw Mal off of a bridge. Carlos dives in to save her while Evie and Jay distract the crocodiles. When Mal is underwater she sees a cave a deduces the hidden opening to the tunnel must be on the shore. The members of Yen Sid's class help them locate the tunnel entrance. Before they enter Yen Sid gives them the maps his students made and offers them each some words of wisdom. The group enters the tunnel and makes their way to the first challenge which is Evie's. She retrieves the magic apple but is sent into a dream where her friends have abandoned her, she remembers what Yen Sid told her and defeats the power of the talisman. The others each defeat their tailsmans and Mal has to get a dragon's egg which is her talisman. When they emerge from the tunnel they come face to face with Ben and Merlin.
Ben informs the group that the dragon lives in the tunnel but the group didn't see it. Merlin gets ready to seal the tunnel when purple smoke appears and Madame Mim materializes. The two get into a magic battle and Mim traps Merlin in a cage. Mal and company debate on Isi g their talismans but realizes the magic will probably turn them evil without redemption. Merlin gets out of his cage and casts a spell to send Mim back where she belongs and seal the tunnel.
When the group arrives back to Auradon they use Evie's mirror to try to locate their parents again because they didn't see them in the tunnel. Their parents are back in their houses and the group figures the villains had followed them through the tunnel so when Merlin cast his spell they were sent back to the Isle along with Mim. They notice a goblin giving Jafar something and realize its the remote that opens the magical barrier from the Isle of the Lost to Auradon. Luckily the remote is broken and hopefully Jafar won't figure out how to fix it. Mal is stunned to see the dragon's egg she had to retrive is starting to turn green which means its hatching. The story ends with a line that Yen Sid told the group on the island, "We're anti-heros, were the villains you want to cheer for."