Jeff Light’s review published on Letterboxd:
This is essentially two separate movies that happened to be made at the same time. They share almost nothing in common, from actors to sets to even the style of writing and directing. It's really kind of mindboggling. They also have little to do with November 5th and the Gunpowder Plot, despite the catchy title. Doesn't mean they're bad though, despite being TV movies. They're a good sort of Nov. 3rd and 4th warmup before watching something like V For Vendetta on Bonfire Night itself.
Movie 1: this is essentially a biopic of Mary, Queen of Scots. Somehow NONE of the main players are listed in Letterboxd's details. It stars Clémence Poésy as Mary and Kevin McKidd as her Scottish advisor, Bothwell. Their main antagonist is Mary's half-brother, a literal bastard named James Stewart, 1st Earl of Moray (Steven Duffy). His real power comes from colluding with Queen Elizabeth though, portrayed here is just a straight villain (by Catherine McCormack). The actors are all quite good, though the script is rather scattershot and doesn't always give them the best dialogue to work with.
The story seems to assume a lot of knowledge of the real history on the part of the viewer, so for non-Brits like me, this can be a bit of a barrier. It skips over a lot of things, suddenly advancing months or years, playing like an English History Survey course at times. While individual scenes are good, it doesn't do a lot to build momentum or suspense over the film. Then it has a rather abrupt and indeterminate ending that I assumed would be picked up on in the following film, but wasn't. If you want to learn a lot about Mary I of Scotland (but skip over broad parts like her first marriage), then this is good. However, it has nothing to do with the Gunpowder Plot and is not something I'll rewatch.
Movie 2: this is essentially a political thriller about how James VI of Scotland (Mary's son) rose to power. The actual "Guy Fawkes" story is a tiny part of this, but it's a pretty interesting movie nonetheless. "Bob" Carlyle is the lead as King James, supported by Tim McInnerney as Sir Robert Cecil (his chief advisor) and Sira Stampe as Queen Anne of Denmark (to become his wife). They're all quite good, but especially Carlyle, who gives a committed and compelling performance with James as both a tortured and passionate man.
The chief antagonists are Catholics implicated in the Gunpowder Plot, namely Robert Catesby (played by Richard Coyle), Thomas Percy (Richard Harrington), Francis Tresham (Patrick O'Kane), and Robert "Everard" Digby (Catalin Istodor). These guys are mostly British TV actors, and their performances.... range. The script of this film gives them a lot of dramatic moments, times when the plot could be discovered or when they're being oppressed, but they don't all make the best use of those moments. Emilia Fox is a standout in a small role as a British spy/patriot, and it's an interesting way for the script to introduce the corruption and abuses of the Catholic Church as a reason why Catholics themselves were so disliked by much of England.
The great missed opportunity here is, of course, Guy Fawkes. He's played by Michael Fassbender, who is just magnetic the whole time he's on screen. But he has practically nothing to do and says probably less than 100 words the whole film. He's brought into the plot as 'the experienced soldier fighting with the Catholics in Spain', but his backstory is only teased at. He's built up as this almost mythical presence in this film, but the fact is that his is the name we most remember for The Gunpowder Plot because he's the only one who was caught and confessed. The other "plotters" were chased down and killed, but who really knows if they were part of it or just being pursued as powerful Catholics who could trouble the King? The film certainly is sketchy about some details, so this is all from a highly speculative point of view.
Overall though, this second part to the "mini-series" hit me a lot better than the first. It's more cohesive, builds more tension, and uses a really interesting technique of Direct Address at certain points throughout. Each of the characters get to help the audience understand the history a bit more, which I appreciated. It still assumes a bit of knowledge on the part of the audience, but I found this part more accessible to non-Brits. Director Gillies MacKinnon seems to be a bit more on his game in this part as well, showing more of the verve he was known for with Hideous Kinky, compared to all his TV work. There are some genuinely brutal and/or shocking scenes here, but they're done well and serve the story.
You could watch either of these parts without the other, but I'd especially recommend checking out the latter one. It's nice to see pre-breakout Fassbender, and until we get a proper film of The Gunpowder Plot, this'll do.