Recaps

Pero left Clark’s universe through the portal with Kara, who wanted to explore another Earth. They arrived in a devastated field of debris in space, and Pero realized the wreckage was Earth.

• Kara asked to travel with Pero, and Clark worried about her entering an unknown universe.
• Kara insisted she was ready to go, and Pero created a golden phantom as an anchor for Clark before opening the portal.
• Pero and Kara said goodbye to Clark and stepped through the portal while Clark stayed behind with Krypto.
• Pero and Kara emerged in space among fragments of wreckage, including a damaged Batman cowl.
• Pero identified the debris field as Earth, leaving Kara shocked by the sight of the destroyed planet.

Pero and Kara found the remains of a destroyed Earth and glimpsed a phantom Earth showing a battle between Superman and General Zod. Suspecting the planet had been destroyed when universes collided, Pero tried to reverse time by flying around its reignited core, and the scattered debris began to reassemble.

• Pero showed Kara a torn bat cowl among Earth's remains, and she realized the planet had been shattered like Krypton.
• A phantom Earth flashed past them, revealing Superman fighting General Zod in a city before both combatants noticed Pero and Kara.
• Pero recognized the scene from Man of Steel and suspected this Earth had been destroyed in a collision caused by the Flash's time travel.
• Pero moved Kara to a safe distance and explained that he intended to try something unusual.
• Pero used Heat Vision to reignite the planetary core, then flew around it at immense speed in the opposite direction.
• Kara watched the debris converge and form the outline of a planet as the shattered Earth began piecing itself back together.

Pero restored Earth by reversing time, then brought Kara back to the moment before the planet’s destruction. Barry Allen, revived after dying in the Speed Force, tried to find his younger self and save Superman, but Pero and Kara’s arrival threw the battle into chaos.

• Pero reversed time until Earth and the solar system were restored, then told Kara they would return to the moment of Earth’s destruction.
• Barry Allen remembered dying to a metal-covered monster in the Speed Force and realized he had returned to the battlefield.
• Barry searched for his younger self, suspecting he could become the monster, and resolved to save this world’s Superman.
• Four massive laser beams destroyed Kryptonian spaceships above the battlefield, bringing the fighting to a halt.
• Kara and Pero descended onto the battlefield, and Barry despaired that their arrival had changed events beyond his understanding.

Pero stopped Zod from stabbing the first Kara to seize the Life Codex, and Kara from the Gunn Universe struck Zod and defended her father’s actions during Krypton’s destruction. Zod recognized her as Kara Zor-El and was left confused about the other Kara.

• Zod grabbed the first Kara and tried to stab her to obtain the Life Codex, but Pero stopped him and snapped his arm blade.
• Zod attacked Pero, but Kara from the Gunn Universe slammed into Zod and sent him crashing across the wasteland.
• Zod demanded to know who the second Kara was and accused the House of El of failing Krypton.
• Kara told Zod that Zor-El had saved Argo City and tried to lead its people to safety.
• Zod recognized the second Kara as Kara Zor-El, then looked at the first Kara and wondered who she was.

Two versions of Kara and two versions of Barry converged on the battlefield, leaving General Zod confused and the future Barry convinced that his time-travel changes had doomed the universe. Zod tried to attack, but froze under the intimidating gaze of the armored man who had broken his blade.

• The imprisoned Kara recognized the other Kara’s family crest and hurried to meet her, while Gunn’s Kara greeted her with enthusiastic chatter.
• The original Kara asked who Clark was, then began asking about Carl before two Flashes arrived through the Speed Force.
• The future Barry blamed himself for changing history and ranted that every attempt to alter events led the universe toward destruction.
• Zod roared and moved to seize Kara, but stopped when he felt the armored man’s gaze and sensed his overwhelming power.

Pero told Barry Allen that saving his mother had shattered his original universe and left him trapped in a doomed parallel timeline. The younger Barry guessed that Pero had come from another timeline, and Pero confirmed he was right.

• Zod trembled as Pero's presence drained his courage.
• Pero listed the missing Wonder Woman, Aquaman, Cyborg, and Justice League as signs that Barry's universe was malformed.
• Barry hoped Pero could restore the original timeline, but Pero said Barry could no longer go back and the universe was destined to collapse.
• The younger Barry suggested Pero was a traveler from another parallel universe, and Pero confirmed his guess.

Pero helped old Barry return to the past to correct his mistake, then stopped the collapsing world from being erased by opening gates between countless worlds. Kara and the others survived as the worlds converged, and Pero set out to explore the newly connected realms.

• Pero knocked Zod into space, then opened a rift through time for old Barry to return and correct his mistake.
• Old Barry embraced young Barry, gave him advice, and ran into the time tunnel as the world began to dissolve.
• Kara began to disappear, but Pero froze the collapsing world and opened gates connecting countless realms.
• People across many worlds saw the gates open, while Kara solidified and survived the erasure.
• Pero descended and walked toward the gates, ready to travel between the connected worlds.