The Titanic was supposed to be unsinkable -- the largest passenger steamship in the world, one of the biggest and most luxurious ships ever to operate. For Paddy, Sophie, Juliana, and Alfie, the Titanic is full of mysteries -- whether they're to be found in the opulent first-class cabins and promenade decks, or the shadows in the underbelly of the ship. Secrets and plans are about to be revealed -- only now disaster looms, and time is running out. The four of them need to find the truth, unmask the killer...and try not to go down with the ship.