Rob and Anna have just met Owen and Kim. Now they've boarded their handsome old boat to travel to a far off island in the Caribbean. With only the four of them on board, it should be paradise: lazy afternoons spent snorklling: long nights enjoying the silence and solitude of the sea. But why does Owen never sleep? Why is he so secretive of his past? And why does Kim keep a knife zipped into her money-belt? Anna can usually get people to talk, but this time, does she want to?