There is a mansion in the middle of nowhere called Vendetta House, tasked with the sole purpose of taking in kids like Ariel: Cambions, the offspring of demons. The day that Ariel turns eighteen, she not only discovers her abilities as a Cambion, but she is taken to Vendetta House, kicking and screaming. Gifted with telekinesis, telepathy, and elemental control, demon-bloods are removed from society for their own good, or so Ariel is told. But Ariel has bigger problems than her hostage situation. An abandoned section of Vendetta House hosts hundreds of dead spirits, ghostly remnants that only Ariel and another strange boy can see. Since her arrival, the dead numbers have been rising, and coincidentally, kids within the House are going missing too. With the help of her new friends, Ariel must uncover the secrets of Vendetta House, or before they know it, they may just disappear too.

Luca Fern has been a girl with a morbid fascination for disguises ever since a case of mistaken identity lead to her mother's murder. Moving to Bottle Island was supposed to heal her obsessive behaviours, but instead it has revealed a mystery that could swallow her whole. As tradition on the island, Altswood High School organizes an annual game called the Hunt: a thrill-seeking contest among peers of seek and eliminate. But this year, instead of an innocent paint pellet, players are being eliminated permanently with bullets to the head. The head investigator, Luca's own father, is stumped as the death toll increases. Soon Luca will be next, and if she cannot bring light to the hidden secrets within Altswood High's traditions, then she too will die in this twisted version of the Hunt.

The core survivors of the Bottle Island massacres lived happily ever after, but there is still one more story to be told. In the fourth instalment of the Altswood saga, Annabelle Martinez and Jules Sodrepena may have left Altswood, but the psyche of Altswood is unlikely to ever leave them. It is their senior year of college and they are en route to Venice, Italy with the rest of their class as part of their final Art History project. Annabelle can't wait-they are graduating in mere weeks, so she doesn't really care about doing well in class anymore. She just wants to sit back and relax, which includes not admitting to herself that she may or may not have developed a crush on Jules, whose new girlfriend is also on this trip. If only the universe didn't hate her. Within her first few seconds in Venice, Annabelle collides with a man running for his life. Just before he dies in her arms, he whispers: "The cipher is in the phone." Annabelle had sworn to herself she would never get involved with another investigation regarding a killer running rampant on a paradise island. But as the situation turns from a murder investigation to a bomb threat that could destroy the whole of Venice, the authorities continue scratching their heads with no solid leads. What Annabelle overheard could be the key to solving this mystery, and preventing the whole island from blowing to smithereens. With only twenty-four hours before the countdown ends, Annabelle and Jules take it upon themselves to uncover who killed the man and why. Their talents for sleuthing in Altswood have followed them to Venice, and there is no time to spare. Only as the seconds tick away, it would seem both the island and their friendship are at risk of falling into pieces.

For eleven years, Oakley Farrell has been silent. At the age of five, she stopped talking and no one seems to know why. Refusing to communicate beyond a few physical actions, Oakley remains in her own little world. Bullied at school, she has just one friend, Cole Benson. Cole stands by her refusing to believe that she is not perfect the way she is. Over the years, they have developed their own version of a normal friendship. However, will it still work as they start to grow even closer? When Oakley is forced to face someone from her past, can she hold her secret in any longer?

Months after the killer of the Hunt has been locked up, a new string of deaths are pulsating through Bottle Island. This time, the police are quick to insist on simple causes: suicide, accident, unexplained heart attack. Anything except murder. But Luca Fern is seeing a pattern. The winter break has arrived and boatloads of tourists are settling on the island, creating a stream of faces that come and go. When a previous victim of the Hunt returns to Altswood and unveils a revelation, it is clear that the case has not been solved. Bottle Island has more secrets than truths, and Luca refuses to believe her paranoia has finally won over her. The Hunt has come to an end, but the killings have not.