Timeflight is simply... a disappointment. The final story of the season promised an adventure utilising the modernistic Concorde, finally returning Tegan to her contempory time. It also saw another visit from The Master, although the reasons why he's here don't really make sense. Time-Flight, in the proud tradition of serials with "Time" in the name, suffers from shoddy production value, a nonsensical and hole-filled script AND from a general sense of Hubris.
One of the serial's biggest faults is the design on the main set, based in Jurassic England. It looks incredibly fake, even by 1982 standards, and this is so contrasted by the really quite lovely modern filming around Heathrow Airport. The use of concorde itself is so gimmicky and yet never really gets a decent hearing. This is made worse by horriffically bad special effects. One consistant effect used is very clearly a filter of soapy bubbles, which just makes it look like the character is having a nice bath. Another part of the story is The Master's use of illusions, which is applied inconsistantly and is used, as it would later be in The Five Doctors, to provide flashbacks for previous characters - including Adric.
At first it appears that the villain is a terribly made-up character called Khalid, who is written as a thin Arabic stereotype. He's then revealed to be The Master, and one has to wonder why the hell he's disguised at all other than to fool the audience. It's a collossal waste of time. The character would go on to use a similarly useless disguise in his next story, The King's Demons. I don't know. Maybe he's a cosplayer? Regardless, the disguise means that the actual Master doesn't get as much time to interact with The Doctor as we'd like, which is sort of the main point of his character. They interact more than they did back in Castrovalva, but it's still not good.
Time-Flight is a very poor end to what is otherwise an excellent season of the science fiction giant. It used sets that were terrible for the time, a story that made little to no sense and a series of events that directly contradicted each other. Even worse, it wasn't horrifically bad in a way that I can enjoy. It was simply terrible, in the dullest way imaginable.
IN TWO WEEKS: I begin Season 20 with the Arc of Infinity.
P.S. "The Master has finally defeated me" is the worst line of Season 19, even with Adric.