Professor Kelvin McIntyre, also referred to as Mac, was an archaeologist on Lord Barset's expedition on the Fortitude to find out what happened to the expedition led by Barset's grandfather.
In 2012, the expedition unearthed the Seventh Doctor and a group of rogue Ice Warriors led by Lord Arakssor and revived them from the ice. When the Doctor realised the trouble everyone was in for awakening the Ice Warrior war criminals, the Doctor, Ben Hodgson, Mac and Genevieve Marceau escaped in Aristo One to try and reach The Fortitude.
When Aristo's battery began running low, the four were forced to abandon the vehicle and travel on foot. Realising that he would just slow the others down, Mac collapsed in the ice and died. (AUDIO: Frozen Time)