It was originally planned in season 23 that the Brigadier would appear in Colin Baker's second season, but the hiatus sort of messed that up and we got Trial Of A Time Lord instead. So we didn't get a Brigadier (or UNIT) story for six years after The Five Doctors, in Battlefield. If I remember correctly, the story was going to be set in Singapore (Hence continuing the JNT pattern of filming outside England at least once a season) and possibly involve the Master and the Autons teaming up again (With the Rani along for the ride too). I think the intention was for Robert Holmes to write it. Not sure if it, like Mawdryn Undead, would've not featured UNIT but instead have something like the Fifth Doctor stories where he was retired. But unfortunately the Sixth Doctor 'skipped' Lethbridge Stuart, who appeared again in the final season opener, Battlefield (and indeed this was his last apearence in Doctor Who, old or new, although he did appear in the spinoff Sarah Jane Adventures and was certainly mentioned a few times in the Sontaran episodes-and his death was mentioned in The Wedding Of River Song etc...although we do have Kate) Of course there were many attempts to rectify this. Dimensions In Time and the Doctor In Distress song both featured Nicholas Courtney briefly with Colin Baker, and of course there were a few novels and audios which united the two. How do you think a Sixth Doctor UNIT story would have unfolded, if the original plans had gone ahead? I haven't listened to the Sixth/Brigadiar audios yet, but I'm kind of curious as to how things would've gone.