Dolly lives with her aunt, who is a seamstress. The child is sent home from school because she has been naughty, and finds her aunt in the act of making a Red Cross costume for a huge mechanical doll. The doll can walk and talk and excites Dolly's interest intensely. Some of her playmates come and run away with the doll, which is later smashed by a runaway horse. Dolly then dresses in the Red Cross costume, hides in the big box, and is taken to the rich woman's home. She reveals her secret to the daughter, a little girl who is sick. The fairy story touches thrown in here are very fine and will appeal to the imagination of small observers. Dolly carries out her deception successfully at the Red Cross bazaar, but later is kidnapped by a gang who have been raiding the house of the wealthy woman. Dolly assists in rounding up the gang.