The Doctor (Full Fathom Five)

The Doctor was a Time Lord that believed that the ends justified the means, willing to kill people for mistakes they had made or dangerous experiments that they had been involved in even if they regretted their actions and showed no sign that they would repeat their errors. (NOTDWU: Full Fathom Five) He wore a midnight blue velvet jacket, a panama hat and had long dark hair with wisps of red. (PROSE: Sustainable Energy)

Having been cut off from the TARDIS when the facility where he had landed, the DEEP, was lost and presumed destroyed, the Doctor remained on Earth acting as a surrogate father to Ruth Mills, the daughter of Eric Vollmer, who was lost when the DEEP was destroyed. When the DEEP was rediscovered, the Doctor attempted to recover his TARDIS, but when Ruth followed and learned that the Doctor had killed her father on the chance that he might continue the dangerous work being carried out there, she simply stood by as the DEEP's sole survivor broke the Doctor's neck, noting that she would remain and watch the Doctor regenerate as many times as she had to until he was finally dead.