Protect and Survive, by Jonathan Morris, brings Ace and Hex (the Doctor mysteriously absent) to 1980s Britain where they encounter an elderly couple (marvellously played by Ian Hogg and Elizabeth Bennett) building a fallout shelter in anticipation of nuclear war. Our time travellers know, of course, that there was no global nuclear war in 1989, and are therefore astonished when the bombs duly fall at the end of the first episode. From there on we appear to be in Raymond Briggs territory, awfully familiar for those of us who remember the 1980s, except that of course there is a lot more really going on than has first appeared, with time loops, Elder Gods and the Seventh Doctor at his most manipulative. Even when the wrenching narrative has been resolved, there is then a surprise twist at the end leading us into the next story. (Oddly enough the BBC produced an Eleventh Doctor audio about a 1980s nuclear war at almost the same time as Big Finish released Protect and Survive, but it is not as good.)
In Black and White, relative newcomer Matt Fitton brings Ace and Hex, and new fellow travellers Lysandra Aristides (Maggie O'Neill) and Sally Morgan (Amy Pemberton), who have both appeared separately in previous BF plays, to the mysterious land inhabited by Beowulf - at two different time periods corresponding to the two different phases of the poem. Fitton doesn't stick religiously to the original's narrative sequence but it gives him a framework for an excellent story, with standout performances from Sophie Aldred in particular and also from Stuart Milligan, who played Richard Nixon on TV Who last year but here plays a wonderfully camp alien called Garundel. There's lots of timey-wimey stuff going on, and one can't really say much more about it without spoilers, but it's really very clever and well done.
Finally, Gods and Monsters, by Mike Maddox and the usually reliable Alan Barnes, rounds off not only this trilogy but several different strands of Seventh Doctor continuity from Big Finish and the TV stories, with the Doctor and his four companions finding themselves interacting with Fenric on a massive mystical chessboard, where they encounter Wayland/Volund the smith of the gods, Hurmzid (sic - presumably Hormizd was meant), son of the Persian Emperor Shapur I, and loads of Haemovores and Elder Gods. I found it satisfying but not superb. The writing is epic and the cast rise to the occasion, especially Philip Olivier in what we must assume is his last regular performance as Hex for BF; but there is if anything a little too much crammed in, with as a result some fairly important bits being rushed - for instance, I only worked out what happened to Hurmzid on the third time of listening. Having said which, it's unusual for me to eagerly listen again to a BF play to work out what was going on. It's a decent conclusion to the trilogy, and is just slightly overshadowed by the previous two stories.
Alongside these three, BF also released Project: Nirvana, a Companion Chronicle by Cavan Scott and Mark Wright, which gives us some of the backstory of Aristides and Morgan engaging in a raid on behalf of the Doctor which turns into complex timey-wimey stuff. I still bristle a bit at the Companion Chronicles being used as a vehicle to support other bits of BF continuity rather than their original purpose, which was to do stories about those Doctors who were not available or willing to perform using their companions instead, but I guess that argument is lost. I also found Project: Nirvana a bit annoying in the way it switched between drama format and narrated story format, and the timey-wimey stuff meant I sometimes wasn't sure which version of which character was speaking. (And one other minor whinge is that the eastern European geography didn't really check out.) It's decent enough, but really only for completists who have already listened to the main trilogy.
To summarise, this trilogy is one of the strongest sequences of stories BF have done for some time; I should also have said that the soundscapes of nuclear war, Beowulf's swamps, and Fenric's chessboard are tremendously well realised. But I don't think they are a particularly good gateway into the BF audios; this particular sequence really starts as far back as the 2001 Sixth Doctor audio Project: Destiny, also by Cavan Scott and Mark Wright, and while I imagine the new listener who had only seen the McCoy/Aldred TV stories might just about make sense of it, it is really more of a reward for us long-term BF fans.