Aired 23 December 1978 – 13 January 1979

The fifth serial of six in The Key to Time season arc, ‘The Power of Kroll’ is ultimately something of a disappointment, unable to successfully weave together its intriguing notions of religion, racism, and capitalism. Even though it never becomes a chore to watch and certainly still has plenty of enjoyable moments and themes, it’s quite telling that Robert Holmes, himself one of the most successful and prolific writers of the classic series, would leave the franchise for several years following completion of this tale.

‘The Power of Kroll’ initially centres on the conflict between the marsh’s native tribe and the boundless corporate greed of a methane extraction company, both sides amplifying their efforts against each other to include murderous attacks and even genocide. With the legend of the Kroll creating a fanatic death cult and Kroll itself also ending up being the fifth segment of the Key to Time, the giant squid-like creature is quite literally the link between the disparate narratives of the natives and of the Doctor, but these two strands never fully cohere due to the distinct tonal differences involved. On the one hand, the Doctor and Romana find themselves starring in what amounts to a light-hearted action thriller as they escape one trap after another, the Doctor literally singing to escape one such predicament. However, the boiling animosity between the natives and the company is inherently much more serious, especially with the fairly overt remarks about humanity’s worst aspects so prevalent. While the two are balanced well, they each serve to undermine each other, especially when the cynicism of the latter is not fully allowed to manifest.

Satisfyingly, though, the fifth segment is absolutely crucial to the entire story rather than simply an addendum or convenient plot device as in the previous four serials. Indeed, Kroll swallowing the segment gives rise to the entire situation at hand as, after growing to immense proportions, it is responsible for the shift in the swamp peoples’ religion to a more cult-like state as well as for the creation of the vast methane reserves that have attracted the company here in the first place. While this still may not explain everything that the Key to Time is able to achieve or why it is so crucial that it be re-assembled at this point in time, it is refreshing to at least gain a glimpse of the vast power within the segment and its ability to literally change the world around it.

Unfortunately, once the monstrous Kroll actually manifests, the preceding narrative becomes essentially irrelevant as the story shifts from somewhat of an ecological and political morality tale to a more overt horror tale. The differences between the two sides on the planet are essentially forgotten as Kroll becomes the focus, meaning that the swamp people are never given the chance to fully develop either. This race is not even given a true name and nothing about their culture except the fanatic religion is explored in any detail whatsoever. While these people are clearly being wronged, it’s difficult to fully empathize with them when so little is known about them as a whole or individually.

Ultimately, ‘The Power of Kroll’ is an exercise in missed opportunities. There are several profound themes that could have been more thoroughly explored with a bit of tweaking, and the swamp people likewise are begging for more development to become the sympathetic figures intended. Kroll itself does manage to look decently realistic even if the direction minimizes its impressive effects in some cases, but good model work for the titular foe is simply not enough to save the story from the many missteps throughout. The end result is still an entertaining tale, and one that excellently makes use of the central premise of the power of the Key to Time segment, but it certainly could have been much more engrossing with the details already present.