Cline's father and grandfather had fought the Hath. Cline was one of the first people to greet the Doctor and his companions upon their arrival on the planet Messaline. The Doctor showed Cline his empty hands to prove that he was unarmed. However, when Cline saw the Doctor's hands were clean, i.e. didn't have a skin sample taken from them, he forced the Doctor to process his DNA. He made the Doctor put his hand into a machine which took a skin sample, analysed the DNA of the skin cells and manipulated them to create a new DNA pattern which was then used to create a new soldier, Jenny, who was technically the Doctor's daughter as she was made from the Doctor's DNA.