After Johnny Maxwell, a boy in his early teens, finds Mrs. Tachyon, an old bag lady, by a cinema he discovers that her trolley is in fact a time machine.

He goes back to his town, Blackbury, during the time of The Blitz with his friends Stephen (aka Wobbler), Bigmac, Kirsty and Yo-less (possibly because Johnny has been obsessing about the destruction of Paradise Street in a German raid).

In Johnny and the Bomb, Wobbler gets stuck in 1941 and grows up to be a billionaire calling himself Sir John and Bigmac is locked up in the Tower of London as a Nazi spy, but, due to the time travel and multiple timelines involved, where and if this happens is questionable.

His interests include Star Trek, train spotting, Morris dancing, and brass band music.

[2] A reviewer for Horn Book Magazine wrote: "With plenty of loopy logic, off-the-cuff philosophy, and hectic action, this trilogy cap-off is pure fun.

"[3] In January 2006 the BBC aired a three-part television adaptation of Johnny and the Bomb, starring George MacKay,[4] Zoë Wanamaker, Frank Finlay and Keith Barron.

In the history thus created, Simon was jailed in the Tower of London for being a Nazi spy though he is later released; Johnny's grandmother was killed, meaning he no longer exists.