Barry Blake is part of COLA Club, and retains his powers at the end of the fourth book. His ability is vanishing, but not very effectively because he is clumsy and his adenoids make a whistling sound. He is friends with Jennifer Troke. He shares a dormitory with Dax and Gideon in the first two books. Barry and Jennifer like to vanish in class, and are frequently caught in the act, though Mrs Dann is always giving Barry a row more than Jennifer because, as Dax once said, she 'looked like butter wouldn't melt in her mouth'.
In the second book, Dax turns to Barry when Gideon deserts him to show Catherine around Tregarren College. Barry talks to Dax whilst sitting on a stone wall, and sticks up for Dax when Spook Williams attacks him with a wild dog named Chip.
Barry isn't willing to risk getting in trouble, nervously telling Gideon to stop levitating a football over Dax's head in case it fell and he got hurt, in which case both Barry and Gideon would be given a row.
Barry is also the first person to notice Dax's resistance to glamour in the form of illusions.
He is described as tall, a little podgy, with dark hair and grey eyes.
He becomes good friends with Clive during Dowsing the Dead.