Doctor Who episode 468: The Sun Makers – Part Three (10/12/1977)
Leela’s execution by steaming as presented in Terrance Dicks’ novelisation always filled me with horror as a child and went a long way to making this one of my favourite Doctor Who books. For all this is largely a comedy, Robert Holmes doesn’t skimp on the scares, and when it comes down to it, Tom Baker doesn’t undercut them by playing for laughs. The moment when he realises Leela is to be killed in a particularly gruesome way, there are no one-liners or mucking about: he looks stressed out, if anything, snapping at K9 to get on with it, and forgetting any other distraction as he single-mindedly focuses on a rescue plan. None of this feels remotely silly.