Mr Cleaver was a Welsh nuclear adviser, charged by the Government with investigating the Blaidd Drwg Power Station Project. He realised that the power station was badly designed, fearing that the suppression pool would cause the hydrogen recombiners to fail. Thus the containment isolation system would collapse, resulting in a meltdown - a potential nuclear explosion which would take most of South Wales with it. After posting some of his fears on Clive Finch's internet site, by then run by Mickey Smith, he reported his findings to the Mayor of Cardiff, former MI5 operative Margaret Blaine, only to discover as she decapitated him that she was actually Blon Fel-Fotch Passameer-Day Slitheen, a member of the alien Slitheen family and was killed by her. (TV: Boom Town) She covered up his death by saying that he slipped on a very icy patch, which few believed due to the fact that his head had been, ( ironically ), cleaved off.