First broadcast 9th March 1978.<br /><br />Robin searches for the trapdoor to a cellar he's found on council plans.<br /><br />Richard O'Sullivan - Robin<br />Tessa Wyatt - Vicky<br />Tony Britton - James Nicholls<br />David Kelly - Albert<br />Michael Redfern - Policeman<br />Eamonn Boyce - Delivery man<br />Bella Emberg - Dirty Agnes
