Mathew Trewella is a lad adrift, living in the shadow of his brother Pete; fishermen in a small Cornish village. Banned from every pub, his options have run out. Whilst singing to himself at sea on Pete’s fishing trawler, Mathew finds a strange beast: unconscious, clearly female and part human, in the net. Seeing the chance to exploit this, the brothers smuggle it to the local aquarium and, roping in Pete’s wife Nessa, they debate what to do.