Colonel Mace is the commanding officer of a large contingent of UNIT, appearing in "The Sontaran Stratagem" / "The Poison Sky" (2008). He originally seems to view the Doctor as a superior officer, saluting him and taking his orders; however, the two clash and Mace begins to be irritated by the Doctor's manner and repeated casual dismissals of him and UNIT, while simultaneously irritating the Doctor through his overtly militaristic manner and insistence on a combat solution to the situation brought on by the Sontarans (Although both agree that the presence of 'Sir Alistair' would be of great assistance at this time).