As the various members of the Galloway family gather to depart for their annual reunion, years-long tensions and rivalries flare up, as they arrive at the private island home of patriarch Spencer. After receiving shocking news about his end-of-life plans, the group is faced with the resumption of a long-dormant round of cruel family competitions from the past.

Shocking revelations make the Galloway family competition even more difficult, as grizzly discoveries and panic grip the family, and the killer claims the first victims. Meanwhile, suspicions start to mount against one outsider following an unexpected reveal.

Reeling from witnessing a gruesome murder, the remaining Galloway family regroup to try and escape the island. But they quickly realize the competition can't be stopped, no matter what. Seamus and Christy's marriage tensions drive them further apart as more secrets from the past are revealed.

Paranoia and suspicion grow among the surviving group, as another body is discovered and terrible secrets from the past come to the surface.

Still reeling from Birgit's confession, Vincent takes his anger out on a panicked Liv, who searches for her missing mother with Theo. With Florence still focused on Vincent, O'Keefe looks for maternal comfort from Grace. The next contest for the family brings new allegiances and stunning betrayals, as Florence makes a horrific sacrifice to save her own skin.

After discovering Florence's selfish crime, Theo takes matters into his own hands in dealing with his wicked mother. Christy learns more about Aphra's past, with grisly results.

Despite their shared penchant for bloodshed, The Gentleman doesn't spare Aphra from a gory death. Leaving only Grace, Theo, Vincent, and Liv in the competition, Grace finds herself outnumbered and fights to continue the competition, leading to another elimination and the unmasking of The Gentleman.

After revealing The Gentleman's true identity, Theo, Vincent, and Liv face horrific truths about the competition and their family, and the heir to the Galloway fortune claims their prize.