1979 AD! Led by the terrible General Ironicus, the mighty Iron Legion – robot veterans of the Eternal War – have come, seen and conquered the English village of Stockbridge!

Caught up in the mayhem, the Doctor pursues the Legion back through the great Dimension Duct to their place of origin – an alternative Earth where Rome never fell…

But can he survive the horrors of the gladiatorial Hyp-Arena long enough to uncover the terrifying secret at the heart of the Galactic Roman Empire?