The first time Marion sees the dashing and mysterious Tom is in 1950s Brighton. In the shade of the pier, he teaches her to swim, and Marion is instantly enamoured, vowing that her love would be sufficient for them both. Patrick encounters Tom in the Brighton Museum a few years later. Tom captures Patrick's attention, introducing him to a glitzy, refined new world. Tom is their police officer, and getting married to Marion now would be safer for him. He must be shared by the two lovers until one of them breaks and three lives are lost.