In the middle of a freezing cold New York winter, Johnsy, like so many others, has been brought low with a nasty case of pneumonia. As well as having a dramatic impact on her physical health, as one can imagine, it has also adversely affected her mental well-being.

Johnsy has got it into her head that she's at death's door and that it's only a matter of time before she embarks upon a one-way journey from this world to the next. Johnsy's good friend Sue is trying her best to keep her positive, but it's no use. Johnsy has pretty much given up the ghost; she no longer has any enthusiasm for life.

In predicting her imminent demise, Johnsy believes that she will pass away when the last leaf falls off the ivy vine outside her window. As the leaf is the only thing that is keeping her alive, the only thing that connects her to this mortal realm, it is imperative that it not fall. Or, at the very least, it must not appear to have fallen.

Using his artistic skills, the painter Old Behrman paints an ivy leaf onto the wall outside Johnsy's window to give her hope of hanging onto dear life. In the event, he is successful, and Johnsy recovers. But sadly, Old Behrman dies of pneumonia, which he caught while painting the last leaf in the cold and wet.