A man named Otto Rotfeld has smuggled a Golem aboard the Baltika, a ship bound for New York from Danzig, a city in Northern Poland.
You see, Rotfeld is "gangly and unattractive" (1.4), as well as "arrogant, but also lonely" (1.5), so he had to go to a man named Yehudah Schaalman to make himself a wife. It's like a Polish version of Lars and the Read Girl.
The Golem is tall, and although she is made of clay, she looks and feels like a real woman; she is "a slave to [Rotfeld's] will" (1.39) and will "protect [him] without thinking" (1.43).
Aboard the Baltika, Rotfeld unpacks the crate and opens a little envelope labeled To Wake the Golem.
He reads it, and she wakes up. Good morning, sunshine.
Rotfeld barely gets the opportunity to acquaint himself with his newly made wife before he gets appendicitis and dies.
Without a master, the Golem is suddenly able to hear the thoughts and desires of every person aboard the ship: "Each one was like a small hand plucking at her sleeve: please do something" (1.124). She basically feels like anyone working retail on Black Friday.
As most retail employees yearn to do at some point, the Golem considers throwing herself overboard.
Unlike most retail employees, the Golem can breathe indefinitely underwater. So when the ship's officials become suspicious at her sudden appearance, and her lack of a ticket, she jumps off the boat and merely walks ashore to New York City.