Mark and Seth watch part three of the Tom Baker story The Brain of Morbius. This story pays tribute to tropes from classic horror stories such as Frankenstein and Re-Animator.

Solon sends The Doctor back to The Sisterhood of Karn for the elixir that can restore Sarah Jane’s eyesight. Little does The Doctor know he is being set up to be killed so that Solon can use his head to complete the body of Morbius!

Sources: The TARDIS Data Core, A Brief History of Time Travel, and Radio Times