Rebecca Brown discovers a talking toad called Glubbslyme in an old witch's pond. When Glubbslyme tells Rebecca that he is hundreds of years old and can perform real magic, Rebecca imagines how she can get revenge on her worst enemy, the oh-so-superior Mandy who has "stolen" Rebecca's best friend Sarah away from her.
But Glubbslyme turns out to be a bit of a character, and things don't quite work out as Rebecca expected.