“Heaven Sent” (9.11): This one-hander, which found the Doctor trapped in hell, was jaw-dropping in its audacity.
Clara’s death was planned for earlier in the season, until Steven Moffat decided that it would be more effective as a lead-in to the finale.
Donald Sumpter has appeared in Doctor Who twice before playing Rassilon in “Hell Bent” (9.12) – in 1968’s “The Wheel In Space” and 1972’s “The Sea Devils”.
The final montage of “Heaven Sent”, as the Doctor breaks through the wall with one punch after another.
did you spot?
“The imbecile’s gas” in “The Zygon Inversion” (9.08) is a reference to Tom Baker-era companion Harry Sullivan, who created the anti-Zygon gas and the Doctor famously declared an imbecile.