Martha Mayhem (real name Martha May) is always causing chaos. She just can’t help it, somehow chaotic things just happen to her. Martha lives in the small village of Cherry Hillsbottom with her eccentric grandfather, Professor Gramps and her small pet hog Elvis. Life gets really exciting though when, on her way to school one day, she discovers a rather bedraggled-looking witch in a ditch. Griselda Gritch (the witch) tells a thrilled and alarmed Martha that she has accidentally let loose a ghastly ghoul that Griselda was trying to catch – and Martha is going to have to help her to get it back again. Griselda, though, is a rather grumpy and difficult accomplice. Can Martha, with the help of Gramps, Elvis and her best friend Jack (AKA Scrambled Egg Head), retrieve the ghoul and prove herself to Griselda?