Recap: Big Finish Doctor Who The Ultimate Adventure

"The Ultimate Adventure" was originally a 1989 stage play by Terrance Dicks running from March 23 to August 19, performed at first by Jon Pertwee as the Third Doctor (occasionally substitued by David Banks as a non-canon Doctor when Pertwee fell ill in the middle of its UK run) and later by Colin Baker as the Sixth Doctor. Big Finish has faithfully adapted it into a Sixth Doctor Audio Play with only very minor changes to the script.

Terrance Dicks eventually wrote a sequel for Big Finish, called "Beyond The Ultimate Adventure".

The Doctor and new companion Jason (well, the Marquis Jason de Saint Epiman de Sinee de la Tour, rescued by the Doctor from revolution-era France) are summoned by Margaret Thatcher to prevent the kidnapping of an American envoy. The guy promptly does get kidnapped by a Villain Team-Up of Daleks and Cybermen and assorted mercenaries, and team TARDIS accidentally drags along up-and-coming Teen Idol Crystal. They follow the lead to an intergalactic Bad-Guy Bar, where the Doctor's disguise (pointy helmet and all) fails to fool anyone. They pick up a furry alien named Zog, who's had enough of his job at the bar, and go on a stealth mission to trick the Daleks (including the emperor) and get the envoy back to earth on time. Jason and Crys, who've fallen in love at this point, decide to stick together and become a proper team TARDIS.