About to lose his sole possession, his boat, for lack of payments, ex- Coast Guardsman Jim Benson takes a gamble on a fishing charter and removes the boat from the dock despite a sheriff's seizure order. But Jim finds himself with a loudmouthed drunk, Shanks, and his companion, Sally. To avoid paying for the fishing excursion, Shanks stages a fight with Jim and, when Jim puts him ashore at a small Mexican port, Shanks takes off, stranding both Jim (who is out of gas as well as cash) and Sally. The two begin to become "friends in need" and are put up by Alfonso, local innkeeper who is a friend of Jim's. But the town is the base of operations for a gang, led by Bodine and Ortega, who smuggle illegal aliens into California for a profit. Learning of Jim's plight, they offer him money to run 'just one' shipment of these 'wetbacks' across the border - then blackmail Jim to continue working for them. Sally tries to persuade him to tell the police, but he is too afraid and plans to run away, ...