Lieutenant Lucke was an officer in the German Army during World War I. He was abducted by the War Lords and hypnotised into participating in their simulated version of the war where he served under Major von Weich.
He interrogated the Second Doctor, Jamie McCrimmon and Zoe Heriot, and thought the Doctor's story about being time traveller's was nonsense. However, he was convinced of the Doctor's story when he demonstrated his sonic screwdriver on Lucke's pistol. The Doctor, Jamie and Zoe then escaped when they took Lucke's pistol and held him at gunpoint.