Hooklight.

Audio  The audio equivalent of one of those missing adventures or past Doctor novels that head off into directions the TV series couldn't possibly have gone, Tim Foley's Hooklight has the Fifth Doctor and his companions wrapped up in a 12-part story which gives each of them a character progression which will almost certainly be forgotten by the end of the story. So, we have Adric overcoming his nervousness around everyone, Tegan shacking up with a male love interest on some backwater planet for three years, and Nyssa being given the Mara treatment from the titular beastie. Even the Fifth Doctor is emotionally frayed around the edges in a way which he simply wasn't given latitude for on television, even after the teen mathematician died. All four of the regular actors are well up to the challenge, and it's a genuine shame that the practicalities of gap-filling mean that we don't get to see more of these slightly wearier versions of the characters going forward. But arguably the MVP of the whole story is Celia Imrie, who gives one of the best performances from a guest actor Big Finish has ever seen.

The Eighth Doctor's participation is complex and not completely explained by the closing moments. Taking the mantle of the "Oracle", he seems to spend decades, even centuries, on the planet at stake, Morning, nudging events and people in a way which would make his Scottish-accented prrrredecessor prrrrroud. The eye patch might suggest that he's some sinister refugee from an alternate reality, but the injury occurred during a nasty encounter, and, even though he says the Fifth Doctor wouldn't approve of who he's become, this is the real Eighth Doctor. Knowing us completists will have PayPaled our fifty quid for this, they do at least also toss in references to Charley, C'rizz, and Audacity, with a hint that her storyline won't end well either, this Eighth Doctor having already experienced their adventures together. Speaking of which, are we to get future stories featuring him and Davlin Crux (an obvious parody of Captain Jack in the mould of Becky Lee Kowalchik?).

Placement:  Given the references to who the Time Lords are at this point by Eighth, this feels like Hooklight from his perspective happens during the Time War era, and late on when he's in the thick of things.