Books with title Zap! I'm a Mind Reader

Imagine someone could creep inside your brain and access your most private thoughts...Helen Chandler is the shyest, quietest student at Mournfield Sixth Form College. Unfortunately for her, the new girl, Annabel Stott, can read minds. And Annabel is intent on discovering her classmates' secrets so that she can blackmail them. Control them. Or worse...If Helen is going to fight back, she's going to have to delve into what terrifies her the most: the past.

Matt's magic crystal enables him to read people's minds and he is determined to keep it a secret. But he does tell his best friend Cally when she is worried about her parents. Matt offers to find out what they're keeping from Cally. As he tells her about the crystal, he thinks he hears footsteps, but no one is there. When Matt is blackmailed into finding out the answers to the English test, he knows he must have been overheard, He sets a trap for the blackmailer and is horrified to discover that it is Cally. He thinks the solution is to hypnotise her into forgetting about the crystal, but his plan doesn't turn out as expected.