Complete story — includes the ending
Lex Luthor's candidacy for president moves forward as Captain Marvel, the newest recruit of the Justice League appears from Fawcett City and seemingly endorses him, which causes tension between him and Superman, who is extremely distrustful of Luthor's motives. Luthor manipulates Superman into fighting Captain Marvel, with the former being humiliated after discovering that the bomb he defused turned out to be a generator. Captain Marvel leaves the Justice League claiming that they aren't acting like the heroes that he adored. At the end, Batman reveals to Superman that he had been baited by Luthor and Amanda Waller as part of a plot to discredit the League.
Sources and content license
Source and revision history · Adapted from Wikipedia contributors, List of Justice League Unlimited episodes. HTML formatting and reference markers removed. · Content license