Going off on a tangent here, this double episode set the parallel universe signifiers for another show, Fringe, that stated airing a couple of years later. The Zeppelins in particular, but also the in-ear headsets (although without the Cyber-implications) and the need to carry identification.

The later development, from "Doomsday", that crossing over impacts the stability of the parallel universe, also comes into play in Fringe. The Zeppelin escape scene from the episode discussed here is copped almost verbatim in season 4 of the latter show — with Cybermen substituted by zombies.

There is also a time travelling character whose apperances are telegraphed pretty much the same way that Clive (RIP) presents the Doctor in "Rose". It would be shameless, if the creators and writers of Fringe weren't gleefully and openly borrowing from pretty much every scifi-adjacent show out there.

X-files and Twin Peaks are directly referenced more than once, and there are obvious callbacks to Cronenberg's The fly, as well as The Manchurian candidate, Firestarter, Altered states, and more.

Tangent over, the scheduled discussion will continue as planned.

This follow-up is decent. A cliffhanger in usual fashion resolved almost instantly using some well-set up doctor ex machina. Plenty of action scenes balanced by a tense walk through the underground tunnel. Throughout the conversion factory there's references to Nazis - emotionless processing, people walking in unawares, rejection of impure stock, the incinerators. The scene of the lone cyberman being euthanised after its emotion chip gets broken is pretty harrowing. But this is undermined later on when they're running around with their heads exploding when all the chips go down at once.

Why is lumic in a wheelchair throne, he's got a metal body? Thankfully by the end he's standing up and a bit more menacing, but even then he's easily defeated in what must be the 3rd "tense quick climb up a ladder while being chased" of the episode. The most terrifying cyberman was converted jackie, and the subsequent scene of them looking back and being unable to tell which is which is quite sad.

The scene of jake reacting to Rickey's death seemed a bit off for me, I couldn't figure out why, it seemed dramatic and over the top. I read up on the wiki later and realised they were meant to be in a gay relationship. This completely changes the dynamic and the scene, and I wish had been stated explicitly.

At the end we're back to doctor and Rose, alone together. Ending with a return trip to see Mum is good. I imagine happening all the time off-screen, given all the trauma everyone usually gets, so seeing it is nice. Ending on a random shooting star twinkle in the alternate universe is weird and makes no sense, but it got a chuckle out of me.

Other minor things I noticed:

• A news anchor says London is "now under martial law". It already was, we saw military checkpoints in the last episode.
• At one point lumic "declares independence" - this dialogue makes no sense
• The Cybermen in "cold storage" in the underground tunnel is a nice callback to an earlier series episode with the 2nd doctor.
• Lumic is the only cyberman who survives a broken emotion chip - because he was already a psychopath.
• I really like the teardrop design of the eyes,and the moulding of the faces, they look much more disturbing than the old cybermen.
• In "our universe" the cybermen originally come from a planet in the solar system close to earth's orbit. THIS is the subtle reference Pelia should have made in that recent star trek episode with an extra solar system planet.

The first thing that strikes me is that the story here is held together by a lot of wild contrivances. Mickey and Jake get to the roof of Battersea undetected...somehow! Despite normally clanking around, the Cybermen can still sneak up on you when convenient! Mickey's hacking skills (granted these have been halfway established in the past) are strong enough that he can find the override code for the emotional inhibitors in a matter of seconds! Also, he knows how to fly a Zeppelin because PlayStation!

With that all the way, I think the emotional core of the episode is strong. The body horror is executed perfectly, with the "why am I cold" scene being absolutely outstanding (and something that I'd forgotten about, shame on me).

I really appreciated Pete's "rejection" of Rose, even after he learns the truth. It's unsatisfying in a very real sort of way.

I'm less fond of Mickey's departure - it's fine, I just don't care much for Mickey. I do think it would have been more resonant if Eccleston was still the Doctor, since he showed more disdain for Mickey last season.

It was nice that the episode spent some time with Jake, and especially Mrs. Moore. It's a little surprising that we never met their counterparts in the mainline universe.

Lastly...the Cybermen could be a good metaphor for toxic masculinity. Maybe it's time to revisit them.