Teenager Jamie Walsh boards The Sacramentum. He has paid Cormac, a Velorum crew member, to take his position onboard so he can investigate what really happened to his missing sister, who vanished from the same ship three months earlier.

Jamie wakes up with a hangover but is determined to get his investigation back on track. Trusting fellow newbie Vivian enough to let her in on his real reason for being on the ship, they begin forming a plan.

It's a big day on the ship, the captain's ball; Jamie shares an intimate moment with Olly; Vivian cosies up to Lily, risking big repercussions if she's caught.

Jamie gains an unexpected ally on board, who promises to investigate from the inside and get the answers he's desperate for.

Vivian and Lily's relationship reaches new heights; Jamie finds himself in a terrifying situation and must use all of his courage and strength to escape.

Jamie finds himself in a lethal dead end with seemingly no way out. When a surprise intervention brings some momentary respite, he learns that others are in peril.