"Dozens of wealthy passengers enjoy dancing in the ship's luxurious ballroom while a beautiful Italian woman sings "Senza Fine." Away from the party in an outer room, a hand pulls a switch that unravels a thin wire cord from a hidden spool.
Suddenly, the spool snaps and the wire slices across the deck (dance floor) like a blade, bisecting the dancers. A number of them remain alive for several seconds before grasping that they have been cut in half. Only little Katie, a younger passenger dancing with a ship's officer (the Captain), is spared, thanks to the captain leaning down on her when he saw the wire snap. Seeing the fate of the other dancers, she looks up at the officer's face. He looks back at her sorrowfully, as his face splits open at mouth level and the top of his head falls off. Katie then screams, the view from the outside of the ship zooms down underwater, and the film cuts to the present day."
I'm pretty sure the film can't top the scene described above, but screw it: ITV, now.