sentences:  Allen has also guested as a panellist on BBC Radio 4's "Just a Minute", in August 2015 and February 2017.Allen portrayed Oliver Harper, the travelling companion of the First Doctor and Steven Taylor during a limited three-story arc in the Big Finish Productions audio dramas based on the "Doctor Who" series.His character is a city trader from 1966, who joined the First Doctor and Taylor in the audio plays "The Perpetual Bond", "The Cold Equations" and "The First Wave".