Heaven Sent (in-universe)

Heaven Sent was the eleventh episode of the ninth series of Doctor Who. It followed Face the Raven.

Its synopsis noted that the episode featured the Doctor "Trapped in a world unlike any other, the Doctor faces the...". By 10 May 2020, the episode was available on BBC iPlayer along with the rest of series 9. Petronella Osgood had started watching the episode sometime before then. (WC: The Zygon Isolation)

Important note
This is a in-universe counterpart of the real world Doctor Who television story Heaven Sent that exists within the Doctor's universe. It was a visual meta-fictional cameo in The Zygon Isolation, where Petronella Osgood and her Zygon duplicate scroll through BBC iPlayer searching for something to watch.

Information from invalid sources
A child once snuggled up to her mother as she watched Heaven Sent, visibly afraid of the episode. (NOTVALID: 2016 BBC Christmas ident)