The first Zac Power Special Files book, containing two classic Zac stories! In Horror House, Zac's SpyPad intercepts a message from BIG! The address in the message leads him to a creepy house that's full of surprises. Will Zac get to the bottom of BIG's plans? Then, in Thrill Ride, there's a sinister invention at Shark Park that's about to be unleashed! Zac's spy senses are on high-alert. He must ride the scariest roller-coaster, stop the invention and save the world . . .