Is

Isabel Williams (Is for short) is something of a challenge, even for her best friend Robert. As a new girl at a 1970s comprehensive she seems vulnerable, but she soon starts putting her teachers in their place with her amazing knowledge of science, bridges and the great Victorian engineer Isambard Kingdom Brunel. Robert soon finds himself dodging school to visit antiquated lift shafts and getting lost in the science museum in a bid to keep up with his mercurial fellow pupil, who at times actually appears to believe she is Bunel reincarnated. But then, after a showdown in school - over Brunel.