"Old Behrman" is a sixty-year-old curmudgeon who lives on the ground floor of the "squatty three-story brick apartment building" in which two young aspiring artists, Sue and Johnsy, also dwell.
Mr. Behrman is a failure as a painter because for forty years he has intended to paint a masterpiece but still has not begun. To support himself he sometimes does illustrations for businesses, and he poses as a model for the aspiring artists in Greenwich Village who cannot afford professional models. He is a "fierce little old man" who disparages weakness of character in anyone. Notwithstanding his crusty demeanor, Mr. Behrman has a tender heart for the two girls who live above him. In fact, he "regarded himself as especial mastiff-in-waiting to protect the two young artists in the studio above."
When Sue, who has asked him to pose for her, tells Mr. Behrman that her friend Johnsy has become so weak and despondent after contracting pneumonia that she has decided to measure her life by the ivy leaves that fall off a building outside her window, Behrman is incensed: " . . . with his red eyes plainly streaming, [he] shouted his contempt and derision for idiotic imaginings." In his Yiddish accent, he includes Sue in his scoldings:
"Vass!" he cried. "Is dere people in de world mit der foolishness to die because leafs dey drop off from a confounded vine? I haf not heard of such a thing. . . . Vy do you allow dot silly pusiness to come in der brain of her? Ach, dot poor leetle Miss Yohnsy."
But for all his bluster, Behrman has a loving heart. He decries New York as no place for the California girl. When he paints his masterpiece, he declares, they will all go away. In the meantime, he poses for Sue. As Johnsy sleeps, Sue points to the ivy vine that is quickly losing its leaves in the cold winter outside. Behrman and Sue look pointedly at each other.
The next day, it is an apprehensive Sue who pulls up the shade, fearing that the ivy leaves have all fallen. But, there is "one lonely ivy leaf clinging to its stem against the wall." It is enough to encourage Johnsy to fight for her life and get well. When the doctor visits, he tells Sue that Johnsy will recover with good nursing. The next day he declares Johnsy out of danger. Sadly, however, Mr. Behrman has died of pneumonia. The janitor found him the day after he posed; he was soaked and helpless with pain. It was too late for the loving old artist, who finally painted his "masterpiece" that saved Johnsy's life by inspiring her to live with his painted leaf.