Fourteen-year-old Baby Jerry, the son of a sailor, old Jerry, sings a sailor song and selects an anchor to sail to Frisco port. He has never seen the sea and does not know how it looks, but two hundred feet from it the river Sacramento rages.

The boy’s father makes money by transporting people across the abyss over the river in trolleys. An old Jerry's brother dies, and his father leaves for San Francisco to speak with a lawyer, leaving behind his eldest son. In the absence of the father, bad weather flies up - the wind and heavy rain. At this time, the farmers come, Mr. and Mrs. Spillen, they urgently need to move to the other side - Mrs. Spillen crushed his father in the mine. Spouses are afraid not to be in time for the dying, they persuade Jerry Jr. to transport them to the other side.

The kid starts the mechanism, the husband and wife begin the crossing. Suddenly the trolley stops in the middle of the road and hangs over the precipice. The boy searches for a malfunction in the drum on one side, runs to the other side and checks the mechanism drum there, but finds nothing. Spillen, meanwhile, checks the mechanism of the trolley in which he is with his wife. This can only mean one thing: the cause of the breakdown in another, empty trolley.

The boy takes a rope, a wrench and a small iron rod with him.Having somehow reached the trolley hanging over the abyss, he finds a malfunction - one wheel of the trolley jumped off the cable - and eliminates it with a nail that accidentally ends up in his pocket. The boy makes a feat - saves people, and he remains alive.