There are umpteen promenade theatre performances in the UK each year, but how about promenade musical performances? This adaptation of the classic Ealing comedy is purporting to be the first. A site-specific work featuring 100 performers, including local people, which transports its audiences around on routemaster buses. When an unexploded World War Two detonates, buried treasure and an ancient parchment is discovered and Pimlico might just be going up in the world. Kate Golledge, resident director on 'The Wizard of Oz' in the West End, directs.