The series about a wedding party on an isolated island whose members are killed off one by one begins with the guests boarding a yacht and traveling to the island. But before they depart one person is murdered, although no one is aware of the death. Later, the bride's ex-boyfriend shows up uninvited, and the killer claims another victim.
The members of the wedding party go on a scavenger hunt as the killer claims more victims. Meanwhile, Abby meets an old friend who claims she has seen killer John Wakefield, who supposedly died seven years ago; Henry discovers a bloody surprise in his bathtub.
Kelly's death is ruled a suicide, but Abby believes she was murdered. Meanwhile, Henry learns that Trish's dad paid Hunter to come to the island; Trish confronts her feelings about her former lover; and the killer claims a sixth victim.
Henry and his groomsmen go fishing and stumble upon a murder victim and $250,000 in cash, which leads to a debate over whether to take the money or leave it. Meanwhile, Trish and her bridesmaids visit a psychic, who begs Abbey to leave the island because she may be in danger.
Trish and her father are attacked while riding bicycles in the woods. Meanwhile, the sheriff searches for the missing reverend and makes a grisly discovery; Abby learns that her dad has a secret obsession; and a victim is claimed at the wedding rehearsal.
The wedding party is in shock following Wellington's murder, and the sheriff questions potential suspects. Meanwhile, J.D. discovers Uncle Marty's body; Abby and Henry dig up Wakefield's grave because they believe he is still alive; and Cal learns what happened to the engagement ring he lost in the lake.
Sheriff Mills searches for J.D. after incriminating evidence is found in his hotel room. Meanwhile, Abby recalls the day her mother was murdered and learns why her mom's killer, John Wakefield, came to the island; Trish considers calling off her wedding to Henry for good; and Malcolm's secret stash of cash is discovered.
Madison disappears while everyone else prepares to leave the island; Abby receives a phone call and is told that if anyone departs from the island, then Madison will be killed. Meanwhile, J.D. escapes from jail; Sheriff Mills is seriously injured.
A bloody trail leads the surviving members of the wedding party to a series of tunnels underneath the inn, where they search for Madison. Meanwhile, Abby learns a devastating secret when she reads Wakefield's diary, and Shane upsets everyone when he arrives at the inn looking for J.D.
An explosion destroys the marina, while the remaining wedding guests attempt to leave the island on a boat. A sniper shoots at them as they flee to a local bar. Abby searches for her missing dad, and two survivors try to drive to the other side of the island to get a sailboat.
Chloe is kidnapped by Wakefield and the surviving members of the wedding party search for her. At the sheriff's house, criminal records are discovered about one of the survivors, which leads to speculation that the person is involved in the murders.
John Wakefield is captured and put in the local jail, but some survivors learn that he has an accomplice and suspicion falls on Jimmy. Meanwhile, contact is made with the Coast Guard and a helicopter is sent to the island.
The mystery is solved as the series concludes. John Wakefield and his accomplice target the five remaining survivors before the Coast Guard arrives and rescues them.