From the Captain's log - some earlier adventures of the Star-Ship Enterprise on its mission-to explore strange new worlds, to seek out new life and civilisations, to go boldly where no man has gone before.

All roads lead to Rome, it is said, but when a trail of space-ship debris brings Captain Kirk to the polluted atmosphere of a 20th-century planet he is astounded by what he sees.
Seeking the missing crew, he is forced into furious combat to save his own men from being butchered to make a Roman holiday.