Camelot under siege--by Roman soldiers? The Shining Knight recruits the aid of the Justice Society to defend Camelot from the strange attack, whisking the team back in time!
The Star-Spangled Kid demonstrates his cosmic converter belt. After impressing his comrades in the Justice Society of America, the Star-Spangled Kid presents Power-Girl with an emblem for her costume, a stylized letter "P". Insulted, Power Girl crushes it. Having formally resigned from the team, the Golden Age Superman prepares to depart. Power Girl is about to say something, when the Golden Age Flash and Golden Age Green Lantern return from Egypt, with the Shining Knight. Having received a message from Merlin, the Shining Knight informs the team that Camelot is being sacked by the Roman Empire. Despite the danger to the timeline, the Golden Age Green Lantern opts out of the mission, preferring to return to his civilian identity. Leaving Hourman behind,re on guard duty, the Justice Society of America accompany the Shining Knight to the past, via the Golden Age Flash's time vortex device.
On the road to Camelot, the band of heroes is attacked by the Dark Knight of Arkan. After the Golden Age Superman unhorses him, the Dark Knight of Arkan summons his followers. Virtually unassisted, the Man of Steel quashes the "threat" of the Dark Knight of Arkan's forces. When the temperature inside the Justice Society of America's headquarters begins to plummet, Hourman investigates. As suspected, he discovers the Icicle on the premises. Before Hourman can fly into action, the Icicle freezes him where he stands. Arriving at Camelot, the Justice Society of America seeks an audience with King Arthur. Once Merlin has outlined the threat to Camelot from the Roman Empire, the band of heroes heads out to face it. After the heroes have departed, Merlin leads Arthur into a back room, where they can watch the battle on a decidedly anachronistic monitor screen. There, they watch the Golden Age Superman tear into the Roman Legionnaires.
The Justice Society of America is on the verge of triumphing over the Romans, when Power Girl discovers that the Legionnaires are robots. At the Gotham Broadcasting Building, Alan Scott is informed that if he cannot resolve the debts of his company soon, it will be foreclosed upon. The Justice Society of America return to Camelot. There they are attacked by flying crossbows and lightning. The Golden Age Superman shatters the Tower of Camelot, ending the threat. Power Girl crashes into the castle proper, with her cousin right on her heels. Merlin repels them with a powerful force field, which he then traps them inside. The Star-Spangled Kid melts Merlin's wand, but is then felled by a laser weapon, wielded by Arthur. Quickly, Arthur also brings down the Golden Age Hawkman, then the Golden Age Flash, though not before the latter beats down Merlin. With the Justice Society of America defeated, Arthur reveals his true identity to the Golden Age Superman and Power Girl. The face of their true foe is that of Vandal Savage.