After receiving a warning from his virtual self in last week's Extremis , the Doctor must now prepare for the incoming monks invasion in the real world - all while still keeping his blindness a secret from companion Bill. The Pyramid at the End of the World is the second part of series 10's "Monk's Trilogy", co-written by Steven Moffat and Peter Harness . This is the fourth story Harness has penned for Doctor Who , following on from series eight's Kill the Moon and series nine's Zygon two-partner The Zygon Invasion and The Zygon Inversion (the latter of which was also co-written with Moffat).