Eight-year-old Daniel is devastated to find out that his teacher, Miss Sommerfeld, plans to marry and move out of town. He devises a plan: steal the wish-granting magic whistle from Mr. Mandelkow’s workshop and transform into a dragon that can kidnap Miss Sommerfeld and bring her back to its cave.

In the process, however, the whistle is accidently burned. Daniel must return to Mr. Mandelkow for help and pass a series of tests before he is transformed back into a human. In the end, he still must say goodbye to his teacher after all.