Landren (Burrowed Time)
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Professor Landren was an archaeologist who specialised in transport systems. He was hoping to find a missing train of a lost civilisation. He went missing before Bernice Summerfield fell down a hole under a trench. The Unbound Doctor found him in the same hole when he went in after Benny. He was dragged into the walls by strange creatures. (AUDIO: Burrowed Time)