Parts: 2 (50 + 65-minute)
Writer: Chris Chibnall
Airdate: 23 February — 01 March 2020
Production Code: n/a

Doctors: thirteenth
Companions: Ryan, Yaz, Graham

Megalomaniac of the Week: the Master
Creature Feature: Cybermen

Story: Following a lead, the TARDIS crew travel to the very end of the Cyber Wars, where they find a tiny band of human refugees temporarily stranded on an abandoned backwater planet. Desperate to continue evading the Cybermen, the humans are working frantically to repair their ship so that they can continue onward to the Boundary, a legendary haven that they hope will allow them to escape the Cybermen forever.

However, no sooner have the TARDIS crew arrived, laden with protective anti-Cyberman equipment, than two Cyber-shuttles appear in the skies. Before long, the Doctor and her companions are under attack, defenseless, separated, and forced to flee from the Cyber-forces. As they struggle to survive long enough to reach the Boundary, in the hopes of reuniting, the Doctor finds herself sidetracked, and forced to uncover a deeply-buried secret about the mysterious Timeless Child...