A mysterious sickness from the Imaginary World is sweeping the town of Buttonville. Dr. Woo, Metalmouth, and even the sasquatch have fallen ill. According to Mr. Tabby, the only known cure is a griffin's feather, but there is none in the hospital. Keeping an eye out for Maximus Steele, a poacher wanted for crimes against Imaginary creatures, Ben, Pearl, and Mr. Tabby make their way through the Portal. But danger looms on the other side. Can they persuade the griffin, king of the Imaginary World, to surrender a feather? And at what cost? Suzanne Selfors delivers a wild journey filled with mythical creatures and zany adventures that are anything but imaginary. This book includes bonus writing, art, and science activities that will help readers discover more about the mythological creatures featured in The Griffin's Riddle. These activities are designed for the home and the classroom. Enjoy doing them on your own or with friends!