Tread Perilously settles in to watch one entire season of Doctor Who. Season 23, to be exact, the infamous "Trial of Time Lord." This week: Parts 1-4 of the Trial, Robert Holmes's "The Mysterious Planet."

When the Doctor is pulled out of time to stand trial for interfering in the development of younger races, the Time Lord prosecutor, the Valeyard, enters into evidence the Doctor's involvement in the affairs of a planet called Ravalox. Sometime before the trial, the Doctor and Peri land on the planet, which features certain eerie similarities to Earth despite being a couple of lights years away. The inhabitants include scruffy surface dwellers and anemic humans in the underground ruled by the mysterious "Immortal." But does the situation on Ravalox relate to the Time Lords or the secretive mission of space-faring rogue and smuggler Sabalom Glitz? Is Ravalox really Earth?

Justin sees Gallifreyan headgear for the first time. He also considers the episode to be the platonic ideal of Doctor Who. Erik maintains that Robert Holmes created The Matrix. Justin attempts to recreate Peri's accent; which continues to amuse him. Glitz and his partner Dibber also delight. Justin and Erik call out the episodes tendency to ask why viewers are watching irrelevant scenes. Erik warns against using the nickname "The Prince of Darkness" when writing about bad ass bad guys and Justin offers a lot more sci-fi writing tips.