When the operators of a luxury cruise ship ask for their help with a series of unexplainable events, Raven and the team are hopeful that this case, for once, won’t endanger their lives.

As they try to blend in with the wealthy passengers, it quickly becomes clear to Davis, Fionn and the others that there is more lurking in the shadows than they've realised. With the eerie encounters escalating and rising tensions threatening to tear the team apart, time is running out for PSI. Can they save the ship – and themselves – before it’s too late?