(Ps - don't read on if you don't want to spoil it. To paraphrase Skaro's finest, 'seek, locate and enjoy' the stories first if you want to avoid finding out anything in advance)
Essentially the theme is realised through three vivid ideas. John Dorney's A Legion Of The Lost bring us a way to bring back the war dead to fight on and on, Phil Mulryne's A Thing Of Guile centres on a Dalek plot to 'reverse mutate' one of their own back into a Kaled and Matt Fitton's The Neverwhen looks at an experiment in which time itself is a weapon.
It's all juicy material and, throughout, these big ideas are littered with interesting characters and well realised guest turns. It's a consistent set - consistently good that is - and rattles along at a great pace. I had to check a couple of times to make sure each disc was 80 minutes in length, such was the way in which they raced by, even on second listen.
A Legion Of The Lost throws us straight into the action on Vildar, a once beautiful and artistic planet now ravaged by the Daleks who wiped out the hosts with the 'Annihilator'. This is another infernal war device that wipes a species from history while both letting them feel the pain of being erased and letting those left still remember and mourn their loss. It's a grim concept and totally fitting with the bleak Time War backdrop.
Despite an encounter with the returning Varga plants, the War Doctor destroys the weapon albeit being forced to kill Zoe Tapper's Collis in the process. Tapper and Collis aren't gone for long though, and are brought back on Aldris as part of a shady deal between the Time Lords and the Technomancers to revive and renew the war dead.
While it's tempting to get carried away with Hurt up against David Warner - as arch Technomancer Shadovar - Tapper probably steals the show here. She subtly shows how the process has changed her character and Collis rises to the occasion to help to end the whole sordid experiment.
With the Doctor now arrested as a war criminal, Ollistra then whisks him off to try to uncover the mystery of a secret experiment on a Dalek asteroid. This middle story certainly improved with a second hearing even though it is, in essence, a more 'straightforward' mission tale.
Perhaps the only downside comes with the relatively unsatisfying conclusion. Having discovered the true nature of the Daleks' K006 experiment, I think I'd have like the War Doctor to have attempted to have taken him along for the ride, if not only to seen what would've happened in the Neverwhen.
The last story offers a bleak battlefield setting. On many occasions across the six discs so far I've felt the Time War has echoes of the First World War about it, not least the way in which the slaughter continues even when there appears to be little 'point' at face value. This is perhaps the closest we get to that yet, with the combatants dying and then, 'thanks' to the time flux, returning to die all over again.
That same flux means that the weapons used by the soldiers regularly pass through the cycle of technological 'evolution' - with fighters seeing the guns they brandish morphing into sticks or bows and arrows mid assault.
It's is a very neat idea, trumped only by the fact the War Doctor lands in among a group of Kaleds and sets about trying to help them, not knowing what they are about to 'evolve' into. The slow realisation that the hero is 'on the wrong side' is well handled and also goes to show that, to some extent, there isn't always much difference between the warring factions.
Nothing is what it seems and nothing is black and white. The Time Lords aren't the 'goodies' by any stretch and that approach makes for much richer storytelling.
Again, if I wished to be hyper-critical I'd have to say that the dialogue heavy last three tracks of this disc again lose a bit of the momentum built up by the plot to that point. That said it's good to end on a face off between a torn War Doctor and an ice cold Ollistra.
Jacqueline Pearce is even stronger in Infernal Devices than the initial box set and offers a nuanced character that is like few others in Doctor Who history. Part Master, part Monk, part companion, you always know something devilish and clever is afoot when she's on the scene.
The whole thing is, of course, underpinned by another brilliant performance from John Hurt. With the odd glimpse of a playful side - 'I have a screwdriver!' - we continue to get an insight into this embattled and embittered hero. The odd attempt at Doctor-ish heroism is thwarted by the relentless horror of the war and you feel events such as these must lead his character on the path to contemplating using The Moment to end it all.
Hurt's performances - alongside the consistently good scripts - are really helping to expand the mythology of the show into new and exciting territory. Any gripes really are very minor and any fan would surely revel in the chance to enjoy such adventures. Roll on the next box set.
Ps, after a bit of thought the War Doctor's theme tune is growing on me. How about you?