Doctor Who: 10 Most Underrated Eleventh Doctor Episodes

Mark Gatiss' Doctor Who episodes were the definition of hit and miss, with the writer never delivering a consistent stream of high-quality stories, but not exactly crapping the bed on each of his outings either. He had some good ones and some bad ones, and two of his best came during the Eleventh Doctor's era.

One of those was Cold War, a claustrophobic and propulsive episode set aboard a submarine in the early 1980s, with the Doctor, Clara, and the ship's crew being stalked by a dangerous Ice Warrior who has nothing left to lose: Grand Marshal Skaldak.

And it's the antagonist of the piece that lifts the episode up a few notches. Skaldak is, simply put, an absolute badass; he's tough, determined, calculated and sneaky, picking off members of the crew with ease, and with his rock-solid armoured exterior and freaky bug-eyed face, he looks intimidating and spooky and downright unstoppable.

Wisely - with such a tight and hostile environment - the episode starts at full speed, and barely relents until the closing credits. There isn't any fat on these bones, and that sense of urgency means that Cold War is basically a compact thriller movie, making it one of the best episodes you can just whack on and enjoy, with a very small amount of narrative baggage to worry about.