What is the plot of "The Last Leaf?"

In this story, there are two artists who live together in an apartment.  Johnsy (a woman) is very sick.  She believes that she is going to die as soon as the last leaf falls off a vine she can see outside her window.  Sue, her roommate, keeps telling her she's not going to die, but she believes she will.

Their downstairs neighbor is an old man, a failed artist who always says he's going to paint a masterpiece.  He goes out in the night and paints a leaf on the wall behind the vine, right where the last leaf is.  Johnsy sees that the last leaf never falls off and she recovers.

Ironically, the old man dies of the same disease Johnsy had, but at least he painted his masterpiece.