Though there are still an absurd amount of Fifth Doctor stories I have yet to encounter, so this statement is far from definitive, this is to date my favourite Fifth Doctor story. It reminds me a lot of the Chimes of Midnight in that both do horror really, really well. This sort of thing is subjective but for me, my favourite type of spooky is done through atmosphere and tension, which I think Iterations of I pulls off expertly. There's a foreboding sense to the whole setting with a creepy island where someone died just after a house was built there and a cult has mysteriously disappeared. That, coupled with Nyssa suddenly and inconspicuously repeating the word "I" leaves you feeling like something is just plain wrong. You want the Doctor and his companions to escape but the TARDIS falls off a cliff so they can't. It's plot convenient but adds to the sense something is very wrong with this island. You know they are in danger, even if the danger isn't all that obvious or present. It's so good.

Then they also get into some really interesting notions of numerology and math. As a fan of such things, this audio was practically tailor-made for me and I just love Iterations of I because of it. I recognize that these particulars aren't going to appeal to everyone, but as someone already familiar with the strange notion of i as an imaginary integer, I was just hooked the second they started getting into such concepts. The Doctor talking about how numbers are sort of imaginary concepts rather than concrete things is not only true but fascinating, and to me is a great little bit of science fiction at its best. It makes the monster and this story wonderfully unique and a real gem of a Doctor Who experience.

All the characters are pretty great too. Our TARDIS crew has a lot of solid scenes, even if there is slightly less for Tegan to do compared to Adric and Nyssa. They run into a group investigating the island and each character adds a little something to the story while also giving us a potential body count to show what could happen to our main characters. Meanwhile, we listen to recordings of someone named Imogen who was investigating these numbers before she disappeared. Her recordings add a lot of suspense and build up on the growing sense of dread and doom that permeates much of the audio. There's something interesting going on with Adric, too. I guess we are setting this character up for Earthshock a bit, which works pretty well here in a tragic way. You can see how a story like this might put him in the head space he was in for that television story nicely. You can definitely tell Waterhouse is much older at this point in making this recording but it hardly matters and he, along with the rest of the cast, all do a great job.

Sure, the plot kind of gets hand waved away at the end and little things do blemish the script slightly - but the positives of the audio to me vastly outweigh the negatives to the point I don't really feel they really hold Iterations of I back. The ending might be a little rushed, sure, but it's interesting, positing a whole little world of beings - some of which are malicious, and others far less so. I heartily recommend this one. It might not be for every one but if these sorts of concepts interest you or if one wants a good story this is a great experience overall.