A deep-sea oil well is attacked by a swarm of lava creatures. The Justice League team is having a difficult time of it, until another group of superheroes arrives. The combined efforts of the Justice Leaguers and the "Ultimen" stop the lava creatures, saving the crew and preventing a major oil spill. During the battle, one of the Ultimen, Wind Dragon, suddenly manifests a new power as the winds he creates become freezing cold.

Afterwards, Wind Dragon gives a speech about environmental responsibility that even Superman finds annoyingly saccharine. The Ultimen then return to their headquarters, and their manager Maxwell Lord gives an interview praising them and making thinly veiled attacks on the Justice League.

Another of the Ultimen, Long Shadow, wants the two teams to be on better terms and seems to be developing a bit of a crush on Wonder Woman. He helps Wonder Woman foil Giganta and Bizarro as they attempt to break Gorilla Grodd out of prison, then talks with her about his interest in joining the League someday; however, he is held back by loyalty to his existing team, who are not interested in a merger.

Maxwell Lord orders the Ultimen to stay in the infirmary for observation while Wind Dragon's sudden power change is investigated. Long Shadow then develops a new power of his own -- super hearing, enabling him to eavesdrop on a conversation between Lord, Dr. Hamilton, and Amanda Waller. He learns that the Ultimen are suffering from cellular degeneration, have at most a few months to live, and are considered "expendable".

The Ultimen leave the infirmary and find a lab containing cloning tanks containing duplicates of themselves -- their replacements. Horrified and angered by this discovery, most of the Ultimen begin smashing everything in sight, ignoring Long Shadow's protests that they are endangering innocent people.

The Justice League arrives to get the situation under control, and manage to overcome and capture the Ultimen. Most of them are taken into police custody; however, Long Shadow remains free, since all he did was try to stop the others and protect civilians from the rampage.

Before the Ultimen can be taken to prison, Amanda Waller arrives with a group of soldiers, declaring that she is taking it from there. The arrested Ultimen are handed over to her; however, the League refuses to turn over Long Shadow. After a tense confrontation, Waller accepts this and leaves.

The episode ends with Long Shadow on board the Watchtower, to spend whatever time he has left with the Justice League.

!!This episode includes examples of:

* BittersweetEnding: Arriving at the Watchtower, Wonder Woman welcomes Long Shadow into the Justice League, to live out his dream and be a true hero for as much time as he has left.
* CurbstompBattle: Downpour vs. Aquaman. One has water powers, the other is at his best in water. Worst possible matchup.
--> (Downpour hits Aquaman with a torrent of water, but stands unaffected)
--> Aquaman: "King of the Seas, remember?" (Downpour [[PunchPunchPunchUhOh recklessly punches at Aquaman, who continues to stand unaffected]] before flooring him with a slap for his troubles)
* [[DugTooDeep Drilled Too Deep]]: Aquaman complains that the attack of the lava creatures was the fault of the drill operators for carelessly drilling into magma without considering the dangers. How dare they assume that the mantle isn't filled with giant lava monsters?
* JustFollowingOrders: Max Lord's defence of his actions. The Ultimen are not impressed, and only spare him because he's not worth the effort of killing.
* MythologyGag:
** The Ultimen are [[{{Expy}} based on]] the original characters created for the ''WesternAnimation/SuperFriends'' show:
-->''Downpour & Shifter:'' Zan & Jayna (the Wonder Twins)\\
''Juice:'' Black Vulcan\\
''Long Shadow:'' Apache Chief\\
''Wind Dragon:'' Samurai
** Also, the Ultimen headquarters resembles the Hall of Justice, and the Justice League members seen in the episode (Batman, Superman, Wonder Woman, and Aquaman) are the same ones who appear in most of the earlier seasons of ''Super Friends'' (except for the presence of both Batman and Robin in the latter).
* NewPowersAsThePlotDemands: Long Shadow's sudden super hearing cues him in on the dark secret behind the Ultimen's creation. More generally, the sudden shifts in powers may be another part of the ''Super Friends'' mythology gag -- on that show, the writers and animators were rather slipshod about keeping track of which hero had what power.
* NotWorthKilling: Juice seems ready to kill Lord for using them, but Long Shadow argues he isn't important enough for them to bother.
-->"No; he's nothing. We want the ''big'' fish."
* SlimeBall: The League is understandably unhappy with Maxwell Lord's cheap shots, and consider him to be a cynical money-grubbing hack.
--> '''Superman:''' I can't listen to anymore of this. This guy's dripping more oil than that platform ever did.
* TomatoInTheMirror: The Ultimen discover that they were created recently with false memories of a normal life. They don't take it very well.
* TheVillainKnowsWhereYouLive: Waller warns Batman against investigating her activities and addresses him as "rich boy", implying that she knows his {{secret identity}}.
* YourDaysAreNumbered: The Ultimen's bodies are breaking down, dooming them to die -- perhaps in days, perhaps in months, but certainly not very far in the future.