The TARDIS arrives in Gaul in 451AD, on the eve of battle between the
forces of Attila the Hun and those of the crumbling Roman Empire. But
the Doctor soon finds that both sides are being helped by sinister,
While Graham makes allies in the Roman camp and Ryan is pursued by
the enigmatic Legion of Smoke, the Doctor and Yasmin are pressed into
service as Attila’s personal sorcerers. But the Doctor knows there is
science behind the combat magicks – and that the true war will pit all
humanity against a ruthless alien threat.
Featuring the Thirteenth Doctor, Yasmin, Ryan and Graham, as played
by Jodie Whittaker, Mandip Gill, Tosin Cole and Bradley Walsh.