to freeze him instantly. Realizing that J.D.'s death is neither accidental nor part of the training simulation, the group heads to the dock to leave the island, but the boat explodes before they can board. After returning to base, the group realizes that the broken watches and clocks found at each scene point to the fact that there's a real serial killer on the island, who has co-opted the training exercise and is now hunting them down. The killer's M.O. indicates that they plan to kill someone at a time designated by the broken clocks. After a thorough search of the island reveals nobody else present, the group concludes that the killer must be one of them. Suspicions initially point to Gabe, as Lucas found maps and documents of the island in his luggage. However, as the group confront him, they all pass out as their coffee has been drugged. They awaken to discover the killer murdered Rafe while they were unconscious, draining his blood and leaving his severed head on a table, leading suspicions to return again to Gabe. Despite the suspicions, Gabe saves Vince from another trap involving broken water pipes and electrocution. Bobby is instead killed by a secondary trap when he goes to turn off the water. Sara deduces that the traps are based on their strengths, talents, and weaknesses, leading the remaining profilers to stick together. After more clues are discovered, suspicion shifts to Sara, who insists that she's being framed. Nicole leaves to be alone, but she becomes the next to die after she smokes a cigarette laced with acid. Unexpectedly, the island's speakers broadcast a taunting message from Harris, making the group realize that he did not leave the island as he claimed. Convinced that Harris is the killer, Sara, Gabe and Lucas search for him, only to find Harris and two other FBI agents dead in a hidden storefront. Harris has been strung up to wires from the ceiling as a marionette, just like the fake "Puppeteer" crime scene they were to investigate. The three turn on each other after triggering another trap and Lucas is shot during the ensuing gun battle. Vince is trapped in a freezer after he tries to reload his empty gun, and soon dies when his gun backfires on him in the elevator. Sara finds Vince's body, but Gabe ambushes her. The two struggle with each other,