A baby girl born with purple hair is promptly handed over to a convent by her horrified father, who fears she bears the sign of the witch. And indeed, little Evelyn seems to have strange powers and to attract supernatural manifestations as she grows up among the nuns, who patiently put up with it as best they can. But after one scary "trick" too many, she is entrusted to the care of a hat-maker, who whisks her off to London, where she will learn about much more than making hats! For as Evelyn and her talking cat Benedict will soon find out, Master Neil has a few tricks up his sleeve, too, and his hat shop might not be exactly what it seems...