I have heard bad things about this story, but the unusual format intrigues me, and I'm trying to go in with an open mind. Trying something different with this review - this is more of a liveblogging type thing, my thoughts as I listen. Skip to the end for an overview/summary. (2/5 - barely.)

White disc
Immediately, the story feels... Incoherent? I'm not sure how to describe it. It's like, a thing happens, and then another, and then another, and it doesn't give you any time to get used to it or contemplate events... It's just... Strange. The premise of the planet that was attacked by aliens who rendered the surface uninhabitable and the Doctor/his companion being assumed to be spies for this enemy alien force feels like it's trying to emulate "Creatures of Beauty". I doubt it will succeed.

I'm sorry, these humans are... Not holding grudges, and... Trying to bring about... Peace??? Humans??? If there's one thing we know about DWU humans, it's that they always want revenge. I just can't buy this. It feels beyond unrealistic.

Something about the oppressive regime effectively suppressing Christmas and then the last hope for peace and salvation being dressed up like a Christmas tree while one of the pacifist members sings a hymn... I wish I could take this at face value and assume it's going to be a story about the horrors of suppressing people's faith (and their hope), but bitter experience (and the warnings I've been given about this story) make me fear otherwise. Alarm bells are ringing.

It feels like the Doctor and Mel are just there to hear the drama.
Oh no, the time field is highly unstable! I'm so scared! /Sarc
Honestly, nice use of time travel. I wish Doctor Who did time nonsense like this more often, it's always so much fun! Shame it's ruined by this "this and then this and now this" nonsense style of writing.
Oop they ded
Why is the only woman in a position of power in this story (so far at least) a manipulative cheater.
EVERYONE GIVES IN TOO EASY. Humans are not really like this. Has this writer never met a human.
"The ends justify the means." And that's bingo!

Ah okay, here's the racism - yep, this is. This is not good. Basic respect towards immigrants framed as a bad thing, with the immigrants as evil invaders... Yeah, this is. Why was this story made. There's something about the blind aliens acting as helpless victims who can't do anything without the humans... This audio is awful.

Okay, this bit is actually quite good - the way Reed and Stewart are disgusted by their alternate selves' own actions, the way people become so different depending on the situation... I am a big fan of the idea of an adventure taking place during another adventure - that's very fun.

Mel's role seems to be just to ask questions (and accidentally give away information) - while this is a common role for companions, I can't help but feel like she should be Doing Something in the story. Ah well, maybe that'll change in black disc... Though, I don't have much hope given the story so far. The fact that the events in this story couldn't have happened if it weren't for the Doctor's arrival (because the TARDIS was necessary) is good, I like that - it's always annoying when the Doctor is just kind of. There. A bystander with no real role to play.

Black Disc
OH HELL NO. The immigrant aliens who are "taking over", who have their culture taught in schools... They don't celebrate Christmas (with an emphasis on "Christ"), and so they're ordering it cancelled. Read that again. This story has immigrant aliens who do not celebrate Christian holidays, and are oppressing the Christian - sorry, I mean human - population. My anti-Semitism bells are ringing. I feel disgusted. This is feeding into every stereotype and right-wing conspiracy about immigrants (and with the big noses on the cover, especially Jewish immigrants, although this could just as easily apply to any non-Christians). "Thanks to positive discrimination" all the humans are slaves... I need to lie down.

Okay, here comes the cool time travel/character stuff again. The original Reed and Stewart were going back in time to save Bailey, and this time, they're going back to kill her. It's gorgeous, it's perfect - if only it was happening in a story that wasn't so incredibly racist. This whole story is just "Christianity is dying. Because of Woke" and I want to scream. Why was this made. Why was this written. Why was this ever allowed. It is horrible to know that this came out of the same company who has done such wonderful audios as Creatures of Beauty and Jubilee. I just can't comprehend such variety in quality.

Ooh okay, another interesting concept being touched on - free will. "Pre-determinism is merely a philosophical abstract, and the physical reality of the universe is one in which all potential actions are permitted, including those whose effect is to cancel out their own logical cause". That line should be required reading for anyone trying to deal with paradox nonsense and fixed points. It's put very well.
Ah, finally, answers to questions raised by the white disc!
This is interesting - the whole time travel thing means that the Slithergee never commited that act of war, never assassinated Bailey... At least, in the original assassination attempt. Of course, the one thirty years later is quite a different story.

Wait, so, the Doctor knew to confess to being an enemy spy because he'd heard that he had before... grandfather paradox nonsense fr. Also, ngl I'm getting confused by all these different sets of Reed and Stewart/the Doctor and Mel. I've lost track of how each set know what!

"Why isn't there another Doctor and Mel here?" Ooh, are we finally getting an explanation? Nope, it's the same as the bit from the first disc. "Too dangerous, too risky, and far too confusing" oh, how ironic that to avoid confusion, you've made it more confusing!

It really does seem like there are just two versions of Mel and the Doctor running around now. It's not like they exist in alternate timelines - after all, the entire point of the ending (both of them) is that there is another set who might solve everything! And it's a key plot point - there have been times where we had both sets on the same version of Puxatornee at once! Very confusing. Am consulting canon-welding-current-spoilers in the big server for this one (will update if we figure it out).
EDIT: I FIGURED IT OUT I AM A LIVING LEGEND I'M THE SMARTEST PERSON ALIVE (see below)

War timeline = the one where they went to war, appeaser timeline = the one where they didn't. War!Dr+Mel arrive in the War!timeline, go back in time, create Appeaser!timeline where Appeaser!Dr+Mel arrive just as War!Dr+Mel come back (and quickly leave to make way for their new counterparts). Appeaser!Dr+Mel then go back in time and change history, creating the War timeline. They then return to the future in the new war timeline, just as War!Dr+Mel arrive, so they leave to make way for them. It's a paradox! It's a circle!!!! Even though multiple sets of Doctor+Mel shared timelines at the same time, they left in different timelines!

Summary
Well, uh, just as racist and awful as I was warned. Jeez. It did have a coherent plot that was easy to follow (most of the time, anyway), and the voices were clear and distinguishable. Fun use of time travel, and innovative story structure/presentation - shame it was wasted on such awfully hateful slop. I could give it anywhere from 1.5 to 2.5 stars and it would feel fair - if it wasn't for all the racism, it would be a good 4.5 or so, but the nonsense really tampers down the score. Giving it a hesitant 2/5, because I have to concede that it would have been a very inventive, interesting story if only listening to it didn't, you know, feel like being hate crimed.

This is part of a series of reviews of Doctor Who in chronological timeline order.

Previous Story: Bang-Bang-a-Boom

I'm really conflicted on this one because I adore really timey-wimey narratives that play around with the format and this is a perfect example of a story like that. But it's also steeped in really awful unsubtle politics that go against everything Doctor Who is about. I'm not going to go into it though because I don't think I can do a good enough job to fully explain (other reviews have done it way better than I could anyway).

The timey-wimey gimmick is genius. The idea of a story in which both halves can be listened to either way is fantastic and such a simple idea that it's surprising it hadn't been done before in Doctor Who. There's lots of really fun parallels between both halves and hearing all the pieces fall into place is incredibly satisfying.

My 5/10 rating for this story might seem to imply that I find it mediocre but what it really is I think the time-travel stuff is 10/10 and the politics are downright awful so it averages to the middle. If you can ignore that kind of thing I'd definitely recommend this but otherwise I'd say avoid it.

Next Story: Delta and the Bannermen

Defences from the evil aliens such as “you cannot understand the Slithergee ethic experience, we are being prejudiced against. It is a hate crime.” And portraying them as “heavily armed refugees” was not very Doctor Who in 2003 and certainly doesn’t stand up today. It belittles and undermines language crucial to defending people in racially hostile environments.

I found the gimmick used here was done pretty well, but admittedly it’s been a while since I listen to this one. I recall thinking it’s alright mostly, there are some great bits and the gimmick used here was executed rather well, but overall I don’t remember too much of it to properly judge it.