The one where the Doctor helps to start the Great Fire of London...
The Doctor discharging the Terileptil power pack to zap Mace's gun was nicely seeded in part 2, when he first demonstrated it. It's not 100% clear what the Doctor does unless you remember the power pack scene in part 2 - and remember, that happened a week ago in 1982 - but it's a nice solution to the Doctor's predicament.
Having overcome Tegan's trance-like state by hugging her, he asks how she's feeling. "Groggy, sore and bad-tempered," she moans. "Almost your old self!" replies the Doctor. Tegan may be some or all of these things from time to time, but she's also very practically minded, and is the voice of reason when they are trying to get the locked door open. Tegan suggests the sonic screwdriver (destroyed), then a flintlock (too noisy, she's told), but is having none of the fact Richard thinks he can pick a lock using a safety pin. The flintlock is the best option after all, and if they hadn't listened to Tegan they might have been there for ever!
The Doctor discharging the Terileptil power pack to zap Mace's gun was nicely seeded in part 2, when he first demonstrated it. It's not 100% clear what the Doctor does unless you remember the power pack scene in part 2 - and remember, that happened a week ago in 1982 - but it's a nice solution to the Doctor's predicament.
Having overcome Tegan's trance-like state by hugging her, he asks how she's feeling. "Groggy, sore and bad-tempered," she moans. "Almost your old self!" replies the Doctor. Tegan may be some or all of these things from time to time, but she's also very practically minded, and is the voice of reason when they are trying to get the locked door open. Tegan suggests the sonic screwdriver (destroyed), then a flintlock (too noisy, she's told), but is having none of the fact Richard thinks he can pick a lock using a safety pin. The flintlock is the best option after all, and if they hadn't listened to Tegan they might have been there for ever!