The lights cut out at the wedding reception and a waitress screams after stumbling upon a dead body.

Aoife and Freddy, the anxious new owners of the Folly, prepare nervously for the high-stakes wedding on their struggling island.

Jules confides that she received an anonymous note three weeks before the wedding warning her not to trust Will.

Hannah escapes the crowd and finds Jules's younger half-sister Olivia hiding alone in a cave on the island.

At dinner the night before the wedding, the groomsmen drunkenly discuss the Survival game and someone jokes that no one ever died.

The wedding ceremony takes place without incident, thanks to Aoife's meticulous planning and organization.

Johnno speaks with show producer Piers and discovers that Will secretly intercepted and declined a job offer made to Johnno.

Olivia wanders into the sea during the reception and begins to drown; Will dives in and saves her.

Jules screams at Olivia for stealing attention on her wedding day and then turns on Hannah for defending Olivia.

Olivia's narration reveals that Will and the older man who impregnated and abandoned her are the same person.

Johnno blindfolds Will and leaves him in a cave as part of an impromptu, menacing game of Survival.

Jules overhears Will cornering Olivia at the cliff edge, threatening her into silence and confiscating her phone.

Hannah overhears Will's college friends describe a revenge sex tape and realizes Will is responsible for her sister Alice's suicide.

Aoife finds Will alone in the dark, confronts him about her brother Darcey's death, and stabs him with the cake knife.

Police arrive and take Johnno into custody for Will's murder; Johnno accepts the false blame as atonement for Darcey's death.

Jules and Will, a glamorous couple, gather family and friends on a remote Irish island for their wedding, despite an anonymous warning about Will's true nature. The groomsmen's shared boarding school history grows increasingly volatile as Johnno discovers Will has been secretly sabotaging his career. A near-drowning at the reception exposes cracks in the wedding party, and Olivia's hidden connection to the groom finally surfaces in her own narration. The wedding night storm cuts the power, and Will is found dead, with Johnno standing over the body covered in blood. Aoife, the composed wedding planner, is revealed as the killer, driven by Will's role in her brother Darcey's drowning death years earlier. Johnno is taken into custody as the wedding collapses into chaos and long-buried truth.

The key events behind a celebrity wedding that ends in murder.

The boat captain tells Hannah and Charlie the haunted history of the Folly and its mysteriously vanished religious sect.

Hannah observes that Charlie changes his accent and puts on airs to impress Jules and her wealthy circle of friends.

Johnno arrives for the wedding having forgotten his suit and borrows a spare one from Will.

Araminta stands to give a toast praising Jules's independence, which irritates Jules rather than warming her heart.

The male guests perform a frenetic ritual at dinner, drumming on the table and chanting Latin phrases in a growing frenzy.

Olivia and Hannah take vodka and cigarettes to a cave, and Olivia hints that her real pain goes much deeper than a breakup.

Alone outside in the dark, Johnno hears what seems like a ghostly voice and breaks down begging it for forgiveness.

Will and Jules discover seaweed placed in their bed; Will dismisses it as a prank by the ushers.

Hannah wanders off course during a walk and discovers a gravestone reading 'Darcey Malone, lost to the sea.'

Aoife watches Will openly flirt with her on the wedding morning and recognizes he uses sexuality as a tool of dominance.

Ronan, Jules's long-absent father, meets Will for the first time and makes no effort to conceal his dislike.

Ronan gives a father-of-the-bride speech at the reception that initially angers Jules before his sincerity finally moves her to tears.

After overhearing Will's confrontation with Olivia, Jules rips off her golden crown and stamps it into a twisted wreck.

The ushers stumble upon Jules's mangled crown and a buckled shoe in the storm before discovering the body.

Jules goes to Olivia after all the truth comes out and the two sisters embrace closely for the first time.

As guests travel to the haunted Folly island, unease spreads through the wedding party in small but telling ways, from Johnno's borrowed suit to Charlie's desperate attempts to fit in with the wealthy crowd. The night before the wedding, the guests' collective darkness rises to the surface through drunken rituals, ghostly encounters, and Olivia's veiled confessions to Hannah in a cave. Hannah's walks around the island bring her into contact with the bog, a stranger's gravestone, and the truth about the kind of man Will really is. Family tensions dominate the wedding day itself, as Jules's estranged father arrives, delivers a complicated speech, and forces Jules to confront how much she craves her family's approval. As the night collapses into storm and tragedy, the physical clues scattered across the island converge into horror. Jules and Olivia emerge from the wreckage having finally connected as sisters for the first time.

The hidden tensions and personal secrets simmering beneath the wedding celebrations.

Hannah steps into a bog while walking alone on the island and gets stuck until Duncan and Pete laugh and pull her free.

Jules spots Olivia standing dangerously close to the cliff edge on the wedding morning but deliberately pushes her concern aside.

Jules tears up the anonymous warning note on the morning of the wedding, resolved to let nothing spoil her day.

Will's father confronts Johnno after the ceremony and wrongly accuses him of stealing the GCSE exam papers for Will.

It is revealed that Will himself stole the GCSE papers, not Johnno, establishing a lifelong pattern of Will escaping blame.

Olivia confides to Hannah that an older man named Steven impregnated her and then abandoned her entirely through the pregnancy and abortion.

Hannah tells Olivia about her sister Alice, whose college ex published explicit videos of her, destroying her political dreams and leading to her suicide.

Olivia's narration reveals that she wrote the anonymous note warning Jules not to marry Will.

Charlie drunkenly confesses to Hannah that the groomsmen abandoned him alone, naked, and intoxicated on an island during the bachelor party.

Hannah discovers that Charlie slept with Jules while Hannah was still recovering from the birth of their first child.

Johnno stays alone with Will in the cave and demands to know whether Will deliberately planned Darcey's death by drowning.

Will grabs Olivia's phone and hurls it into the ocean when she threatens to show Jules their text exchanges as proof.

Jules calls Will and Olivia back into the marquee to cut the wedding cake, an act that may have saved Olivia's life.

Aoife and Freddy's true plan is revealed: they lured Jules and Will to the Folly specifically so Aoife could confront Will about Darcey, her murdered brother.

Hannah and Charlie leave the island together, their marriage irrevocably changed; Hannah privately wishes she had been the one to kill Will.

On the morning of the wedding, small but fateful decisions seal the characters' destinies: Jules destroys the one warning that could have saved her, and Olivia's silent guilt becomes clear when her narration reveals she sent that very note. After the ceremony, the groomsmen's shared history unravels as Will's real crimes at boarding school surface and Johnno discovers he has spent years carrying blame that was never his. Olivia's secret affair with Will converges with Hannah's shattering realization that the same man destroyed her sister Alice's life and drove her to suicide. Charlie's betrayals of Hannah emerge as Johnno finally confronts Will alone in a cave about the deliberate drowning of a boy named Darcey. When Aoife and Freddy's true plan is revealed, every thread connects back to Will's lifelong habit of using and destroying the people around him. Hannah and Charlie leave the island together but permanently changed, with Hannah privately haunted by the wish that she had dealt the final blow.