Tread Perilously's annual Tread Merrily tradition returns with the Doctor Who Christmas special "Twice Upon a Time."

As the Twelfth Doctor (Peter Capaldi) resists his coming regeneration, the TARDIS lands him in a very peculiar place: Earth's South Pole in 1985. There, he runs into the First Doctor (David Bradley) as he also tries to avoid regenerating. Soon, the two incarnations land in a heap of trouble, starting with the sudden appearance of a World War I British captain. But when the Doctors and the captain come into contact with Testimony, a memory-scraping AI from the far future, the nature of the problem leads to a startling revelation for both of the Doctors.

Justin declares Freddy's Dead as the worst Nightmare on Elm Street movie. Erik's frustration with ex-showrunner Chris Chibnall bubbles to the surface. The nature of Christopher Eccleston's "return" to the Doctor is explored. Justin learns about the Fourteenth Doctor and the other extra Doctors played by David Tennant. Justin offers some James Bond opinions. Erik and Justin disagree if a person is the sum of their memories or not. World War I becomes an unavoidable topic. VR headgear is decried and "The Ankle-Touchers" makes its debut.