25 September 1965: broadcast of "Air Lock", third episode of the story we now call Galaxy 4. Vicki is captured by the Rills, but persuades the Doctor to help them; Steven is threatened with asphyxiation by the Drahvins. This may be the one episode of Old Who that I have not actually seen since its recovery in 2011.
25 September 1976: broadcast of fourth episode of The Masque of Mandragora. The brotherhood attempt to infiltrate the masque at the gathering of Renaissance savants, but the Doctor and Sarah foil their plan.