This one is not so much a straightforward linear story about any one distinct subject, more an exploration of all kinds of different concepts and themes. Colonialism for one. Obviously this is an issue many previous stories have addressed, but here there seems to be an attempt at a much more sustained and sophisticated depiction of the "victim planet"'s indigenous people, a more determined effort to demonstrate that they are not the "primitives" that Sanders, in particular, views them as. His contemptuous dismissal of the Kinda as "savages" and his incredulity at them having a meaningful point of view are similar to, say, Thawn's attitude to the Swampies in Kroll, but there is also an attempt to trap him in his own logic, re the absurd statement he makes justifying his views "If they're so intelligent how come they haven't colonised us?" In other words, he is unable to assess their worth by any other way than applying his own unexamined value system. The sophistication the Doctor credits the Kinda with in Episode Four can be seen to derive from their understanding of the dangers of dreaming alone by the Windchimes - indicating a spiritual awareness completely lost on the humans in the Dome - and it also helps confirm what we've already been shown, that the structure and belief systems of their society are as complex and "valid" as those of the interlopers, even if they are only imperfectly understood. What the Kinda do not appear to be interested in is anything to do with power or conquest (hence Sanders' incomprehension of them), and the possessed Aris's attempts to rouse this martial spirit are recognised as being, in their own way, as alien an intrusion on the planet's culture as Sanders' party.

The business of the male Kinda being unable to speak, and Panna's claim that being able to speak is "a mark of wisdom" in their case, along with the fact that any male who witnesses the opening of the box of Jhana goes insane suggests a possible feminist subtext to the story too. The nature of Panna and Karuna is also highly evocative of ancient "Wise women" imagery sometimes found in more female-centred mythos (it vaguely reminds me of Gaian thinking, where femininity is a positive creative force, and masculinity is seen as evil and destructive). The Doctor is unusually ready to acquiesce in his being constantly addressed as an "idiot" by Panna, even allowing her to use it as if it were his name. Partly it is no doubt pragmatism on his part, in the face of the urgency of the situation, but symbolically it may also represent the Doctor's deference to their "wisdom". Of course, the fact that the box does not send the Doctor out of his mind could be said to indicate his alien origins, although I think it also represents how "enlightened" he is, and this "enlightenment" means that he doesn't allow relative trivia such as Panna's insulting mode of address bother him.

Further information relating to the Kinda shows that they have seven fathers - which shocks Todd but doesn't seem to phase the Doctor (fitting, as he will have seen a far greater variety of civilisations than her, and has a less insular attitude in general. Even Todd seems initially to object to taking prisoners from the Kinda on pragmatic rather than moral grounds, a hint that she isn't entirely free of colonialist patterns of thinking) - and that they seem to have the ability to pass on themselves to younger hosts on death (Panna and Karuna), which is heavily reminiscent of religious beliefs in reincarnation.

The power dynamics of the colonists are another major theme. Sanders' line, "Meet a few difficulties, suddenly everyone's got an opinion. That's how things fall apart", indicates not only his authoritarianism, but his contempt for any kind of introspection or self-questioning. Authority, power and action appear to be rather more important to him. The fear and the burden of responsibility implicit in the situation have conspired to push Hindle over the edge, and Simon Rouse rises to the occasion with full-throated enthusiasm, developing from a twitchy neurotic with barely suppressed aggression in the first episode to a completely unpredictable raving maniac as the story progresses, abruptly switching moods and attitudes, and displaying paranoid fears of what lays outside the Dome. When the bullying Sanders has returned, having regressed to a docile and mild mannered child, the two of them are shown to have been reduced to their most basic level, sorting out who is in charge and playing at city modelmaking. Unable to function properly as adults, both are trying to recreate a child's world. The paranoia about the outside also fuels the explosives Hindle sets up, to allow him to have the surrounding area devastated at will, and this possibly also reflects a child's defensive aggression against anything it fears or does not understand. It's only at the end, when both character re-appear with rather more balanced personalities, allowing each to overcome their less attractive traits, that we're able to see them relaxed and at ease with themselves.

Another concept the story explores is that of cyclical civilisations. Panna's remark "Wheel turns, civilisations rise, wheel turns, civilisations fall", and the Doctor's explanation to Todd that the vision they see of the end of the Kinda (in which some of the imagery is driven home a little too heavy handedly, via clocks striking twelve and so on) is both the past and the future, both point to this. This seems to be a reference to the belief held by some religions that history repeats itself in lengthy phases lasting thousands of years or more.

Tegan's possession by the Mara gives rise to some powerful and memorable "subconscious" scenes played against darkness, as Tegan is confronted by bewildering images (possibly reflecting her crew mates and her fears of being out of depth in the situations she experiences in general?) and subjected to various psychological horrors that, in splitting her into several, blur her own sense of individuality and identity - and the sequence showing her and Dukkha as lonely outlines in the darkness evinces utter panic from her. The scenes showing the possessed Tegan also give Janet Fielding the chance to play a rather different side of her character, all slyness and a mocking mischievousness manner, and with a vaguely sensuous undertone.

Nyssa's virtual absence and the lengthy time Tegan spends unconscious allow slightly more attention to be focussed on Adric than usual. He shows a knack for conjuring tricks and a certain ability to manipulate Hindle to a limited extent, gaining his trust for a while, and there's something about Hindle's punishment of him that suggests he has awakened sado-masochistic instincts in the other man. It's also interesting that he is not punished any further, in the sense of being returned to the cell after this occasion, and Hindle and Sanders, while still in their disturbed state, seem to develop a strange need to have him around them.

There are production problems - the jungle set is too bright and studio bound-looking, the Dome sets fairly bland, and the final physical manifestation of the Mara is rather poor (it's questionable whether a physical appearance by it was really necessary anyway, and perhaps this was a case of unwisely acceding to genre expectations), but the strength of the ideas, and quality of the writing, directing and acting mostly compensate.