A narrator introduces himself by insisting that he keeps seeing messages in the world around him.
One day while walking to the shore, he glances up and sees a slender white hand waving through the grille of a prison window.
He continues down toward a beach and sees a woman named Miss Zwida.
It seems that he often tries to speak to her, but for various reasons, always chickens out at the last second. Passing by on his bicycle is a man named Mr. Kauderer, who works at the nearby observatory.
Stopping for a chat, Mr. Kauderer offers to show the narrator how to use the observatory's instruments, and before the narrator even knows what's happening, he's taking care of the observatory while Mr. Kauderer is away for the next few days.
Eventually, the narrator works up the courage to speak to Zwida. After a brief but stimulating conversation, he asks her to meet again.
She says she can't the next day, but can do something the day after that. (Sweet!) Later that same day, two men approach the narrator in heavy coats and ask after Mr. Kauderer.
The narrator admits that he doesn't know where Mr. Kauderer went.
It is not long after that, passing by the prison, that he sees Zwida hanging around inside the walls for visiting day. Near her, he also spots the two men who questioned him about Mr. Kauderer. Something's clearly up, but he's not too sure yet.
Two days later, he asks Zwida about being at the prison. She explains to him that she likes to go into the prison and draw the prisoner's visitors.
The narrator accepts the explanation, though he doesn't recall seeing Zwida carrying any drawing supplies the day before.
Zwida turns the subject back to drawing, and tells the narrator that she's interested in sketching a little anchor with four "flukes." She shyly asks him to buy her one, since she doesn't want to openly show interest in crude men's things. She specifies that she wants a rope of twelve meters attached to the anchor.
The next day, the narrator's doctors tell him that he is well enough to drink again.
He celebrates by going to the local tavern, where one of the prison guards brags about a pretty woman who always bribes him to let her visit one of the prisoners at odd hours.
The next day, the narrator asks a man by the shore about buying a "grapnel" like the one Zwida wants.
The other man becomes immediately suspicious, and tells the narrator he won't sell such a thing to foreigners, since it might be used as a grappling hook to break someone out of the prison.
Later, the narrator receives a secret note from Mr. Kauderer, asking him to meet in a nearby graveyard.
That night, Kauderer informs him that on the following day, he [the narrator] will be questioned by the chief of police about trying to buy the grapnel.
Confused, the narrator returns to the observatory and stands outside during a storm. Sensing something moving nearby, he glances down and finds a bearded man curled up on the steps beneath him.
The man claims he has escaped from the prison, and that he needs the narrator to meet someone at the local hotel for him. Again, very interesting stuff…