Secretly tasked with transporting precious cargo across the Atlantic by the Leap Year Society, the crew of the S.S Talaria find themselves dwindling in number by a mysterious illness ravaging those aboard. While the remaining men seek to keep the ship moving, it is Emilia, a female stowaway sneaking in the shadows, who may become their unlikely hero.

Forced out of the shadows, Emilia clashes with the Talaria’s enigmatic doctor, Emmanuel, while stealing medicine for the wounded Amina. She now finds herself caught between those who believe a great power has come to this ship to elevate them, and those who fear a great darkness, known as Seshin, is spreading.

Tensions flare among the remaining crew as Emmanuel proclaims the current predicament is by grand design. Others on board, however, fear their imminent death is closing in. Now exposed, Emilia is forced to take allegiance with men she barely knows or trusts. Meanwhile, Seshin continues to infect the minds of those who have yet to succumb to its wrath.

A common goal fosters trust between Emilia and Thomas. The recovery of Amina’s lost journals raises more questions than answers about what the LYS member knew about Seshin and the dangers plaguing the ship, the same hazards that lead to a violent incident in the engine room that further lowers the crew’s numbers.

The Talaria may be up and running again, but its exact course is as much a mystery as the source of the ship’s curse. Emilia combs through Amina’s journal for guidance but instead, its contents provoke her biggest break with reality yet. Will the ship reach land before Seshin consumes them all?

Emilia searches the Talaria’s labyrinthine halls hoping to make amends with those she’s wronged, but redemption won’t come easily. While she once knew the ship well enough to avoid detection, now nothing is as it seems and Emilia, like the others, falls further and further into despair. Will they ever make it off this cursed ship?

Now down to three crew members, Emilia becomes the focus of Emmanuel’s obsession and the sole obstacle preventing his desired communion with the ship’s disturbing presence. Though the doctor poses quite the threat to her survival, it’s the cargo below deck, containing Seshin, that Emilia must truly overcome if she’s ever to see the light of day.