Herbie is a real pain: when he lures Twipsy into a trap it's just too much. Herbie must mend his ways! Nick, Lissie and Twipsy persuade Hypno the Great to hypnotize Herbie by computer. Soon Herbie changes into the nicest brother in the world - in fact, he's much too nice for the liking of Nick, Lissie, Albert and Twipsy. They try to reverse the transformation ...