Orphaned siblings Henry, Jessie, Benny, and Violet are determined not to be separated after the deaths of their parents. Fearing being sent away to live with their cruel, frightening grandfather, they run away and discover an abandoned boxcar in the woods. They convert the boxcar into a safe, comfortable home and learn to take care of themselves. But when Violet becomes deathly ill, the children are forced to seek out help at the risk of their newfound freedom.

This original 1924 edition contains a few small difference from the revised 1942 edition most readers are familiar with, but the basic story beloved by children remains essentially untouched.