Before I start, a fair warning as of the episodes I shall review this is the one I saw the longest time ago, literally months. I rather enjoyed this episode, despite the flaws. Those flaws being: the awful acting jobs on everyone not The Doctor, Sarah, and Harry; the terrible effects; and the overall meh story. What really sold the episode to me was how it developed The Doctor, Sarah, and Harry. The Doctor had a great line, about how of all the species he's seen, Humans are by and large his favorites. In general it's the episode that acclimated me to Tom Baker's Doctor. With Sarah I felt connected to her for the first time, with her very funny scene of crawling through the vent. And Harry was pretty good too, really playing up the whole Naval Doctor thing. Overall, it's a slightly above average episode for me, but only because of the writing and acting of the leads. Laters.