Pirie was the doctor of a Scottish expedition to Antarctica in 1903.
The "ghost" of Allan Ramsay, the first human to die in Antarctica, took the other members of the expedition, one by one, until only William Cuthbertson was left. The Second Doctor, Jamie McCrimmon and Zoe Heriot arrived on Christmas day. Jamie played the bagpipes, and the others sang along, which brought back the missing members of the expedition, including Dr Pirie. (PROSE: Mirth, or Walking Spirits)