Christopher Benjamin's role as theatre owner Henry Gordon Jago in the Fourth Doctor serial The Talons of Weng-Chiang proved to be one of the more popular one-story companions of the classic series. Paired with Professor George Lightfoot, the two creep around London like a bumbling Holmes and Watson. The characters were later revived for a Big Finish series of adventures and Benjamin also had the one-off audio role of Tardelli in the Eighth Doctor adventure Grand Theft Cosmos. In the modern era, Benjamin reappeared in The Unicorn and The Wasp (2008) as Colonel Hugh Curbishly. He and his wife, Lady Clemency Eddison, host a party at which writer Agatha Christie is the honoured guest. Of course there's a murder and the Tenth Doctor and Donna investigate, all while revealing secrets about each party guest. Speaking of Donna...