CREEPING MAN, THE_BOOK & CD - Illustrated Readers Level 3

Elementary.Why would a dog attack his master? Why would a respected Professor dissapear for two weeks without telling anyone where he went? And why, upon his return, would he begin to act in a strange and scary way, creeping around the house and garden on all fours? Can brilliant detective Sherlock Holmes help the Professor and solve the mystery of the Creeping Man?