Fayson and her friends are back together and ready for their toughest case yet - someone is sending anonymous emails accusing the detective agency of being a nuisance to the island! But when they find an abandoned boat with two wet lifejackets on board, they know they have a new mystery to solve. As strange things start happening on the island, with books and video games vanishing and a suspicious figure lurking around at night, Di Island Crew must use all their smarts to uncover the truth. Can they crack the case and save the detective agency, or will they be forced to close down for good?

Fayson has been dreaming of going back to the island ever since she left. But no sooner is she reunited with Di Island Crew than a mysterious case comes their way - a haunted wardrobe that keeps making a spine-chilling sound.! And to make matters worse, the crew have all received a letter threatening to reveal their deepest secrets. With the clock ticking, Fayson must rally her friends and take charge of the detective agency to solve the eerie mystery. But with tensions rising and friendship squabbles getting in the way, can they work together to crack the case and keep their secrets safe?

Fayson has always wanted to be a detective. When her cousins recruit her to their top-secret gang on the island one summer, her dreams seem to be coming true. But the Greatest Gang of All Time don't live up to their name, and keep getting distracted from missions by things like food, falling asleep and a fair bit of squabbling! Guided by her favourite mystery novels, Fayson takes charge and tries to track down clues about the strange shadow that has been appearing in the island's lighthouse. With tensions stirring within the gang, can she use all her smarts to solve the case?