A boy (Russ Tamblyn), no bigger than a thumb, manages to outwit two thieves (Terry-Thomas and Peter Sellers) determined to make a fortune from him.

In a mythical land, woodcutter Jonathan (Bernard Miles) agrees not to chop down the oldest tree in the forest in return for three wishes granted by the Forest Queen (June Thorburn). After he wastes two wishes bickering with his wife, the third brings them Tom (Russ Tamblyn), a thumb-sized child. The couple dote upon him, but are unable to protect him when, on his way to the village, the innocent Tom falls in with villainous Ivan (Terry-Thomas) and Tony (Peter Sellers).—Jwelch5742