[This review contains some minor SPOILERS!]

The “base under siege” story is perhaps the most well-trotted workhorse among the many plots to be found in Doctor Who. Just throw The Doctor and The Companions into the middle of a remote location ruled by bureaucracy. Introduce a monster said bureaucracy is wholly unequipped to deal with. Watch The Doctor be clever and save everyone by thinking outside the box, while quipping about the limits of military thinking/academia. It’s as basic as yoga pants and pumpkin spice lattes.

Seemingly knowing this, Chris Chibnall attempts to subvert the usual cliches of the “base under siege” storyline to make “The Tsuranga Conundrum” into something different. He is successful in defying the usual cliches Doctor Who runs into in this kind of story but winds up depending on some other general fiction cliches to keep the plot moving. For instance, there’s a subplot that requires a baby be delivered as the power goes out at the height of the destruction. The fact that the baby is being delivered by a humanoid alien from a species where the men and women give birth does little to dress up the base idea and only inspires flashbacks to gags Red Dwarf did on the subject of male pregnancy 30 years ago.

The chief problem with “The Tsuranga Conundrum” is that it tries to do too much. It is rare for me to complain that a Doctor Who episode should have been stretched into a two-parter, but this story could have benefited from having more time to tell the stories of all the characters Chibnall’s script introduces. In addition to the expecting father (who isn’t sure he wants to keep his baby), there’s a legendary general hiding a illness, her ill-respected engineer brother, the general’s robotic attache and a rookie medic with no confidence in her abilities as a healer.

Throw in The Doctor suffering sporadic attacks of pain in the aftermath of a sonic mine attack and Ryan having to confront his own issues with his negligent father and there’s way too much story for just one hour, even ignoring the alien trying to eat the hospital ship where our heroes are trapped. The also episode suffers from continual shifts in tone that ruin the mood. The comic relief of the pregnant alien storyline kills the momentum of The Doctor running around from each crisis, all while fighting the pains as her organs resettle.

Only three things make the episode at all tolerable. First, the direction by Jennifer Perrott is top-notch and she perfectly captures the tone and pacing of each individual scene – the episode only falters when one considers the flow of the story as a whole. Next, there is the performances themselves, which are all well-played and this episode may have the single strongest ensemble of any episode in the season so far, if you ignore the material they have to work with. Finally, for all the flaws in pacing and mood whiplash “The Tsuranga Conundrum” has, Chris Cibnall is to be commended for cleverly hanging a lampshade on some of the usual “base-under-siege” cliches, such as why none of the corridors on the alien hospital ship have signs telling you where to go.  Given all that, “The Tsuranga Conundrum” is not a great episode, but it is a serviceable one.