Mayhem of the Music Meister!

Mayhem of the Music Meister is the fourteenth episode of the first season of NBC's Justice League. It first aired on February 19, 2019. It is the fourteenth episode overall.

Synopsis
The mysterious Music Mesiter arrives in Happy Harbor and uses his meta-human powers to control the Justice League with music. Batman and Wonder Woman work together to stop his plans to spread his song throughout the world.

Plot
The Justice League get an alert that there is a break-in at the Happy Harbor Chemical Plant. Tim, Stephanie, Kate, Mike, and Kara go down there and discover Black Mask, Toyman, and Cheetah trying to steal a dangerous chemical. In the fight, they begin to sing as the Music Meister takes control of them. The Meister then sings about his plan and escapes the D.E.O.'s efforts to stop him and escapes with the chemical and the controlled heroes and villains (The Music Meister).

Bruce, Clark, Barbara, Dinah, Barry, and Diana try to find the Meister but are attacked by Merlyn and Luthor singing about how they never win. The Meister then gains control of Clark and Barry as the two heroes join the latter villains in singing about how the Meister's plan will win (Succeed).

Dinah becomes subject to the Meister's control and sings about her love for Bruce. The Meister hears her sing and kidnaps her to become his partner in crime. Dinah is brought to his bobby-trapped lair with the rest of his goons (If Only). Barbara is one of the citizens of Happy Harbor that is evacuated due to the pandemic. Bruce and Diana find the Meister's lair and rescue Dinah, who has been brought back from the Meister's control but cannot stop singing. However, the heroes are attacked by the controlled heroes and villains but Bruce is able to bring back Tim and Clark (This is a Rescue).

Bruce, Diana, Dinah, Tim, and Clark discover that the Meister is using the chemical to spread his song throughout the world to control the entire planet. The five confront him and some of his goons at Happy Harbor Stadium where they finally incapacitate him, also releasing the goons from his control (The World is Mine). Dinah also finds love in Agent Cameron Chase of the D.E.O. (If Only (Reprise)).

The Justice League celebrate their victory against the Music Meister and the Legion of Doom, who were imprisoned, just as the Legion escape (Off to Work).

Starring

 * Ben Affleck as Bruce Wayne/Batman
 * Joseph Gordon-Levitt as Tim Drake/Red Robin
 * Emma Stone as Stephanie Brown/Spoiler
 * Yvonne Strahovski as Kate Kane/Batwoman
 * Jeremy Jordan as Winslow Schott/Toyman
 * Tyler Hoechlin as Clark Kent/Superman
 * Sarah Hyland as Barbara Gordon/Batgirl
 * Todd Stashwick as Roman Sionis/Black Mask
 * Alexander Gould as Dick Grayson/Nightwing
 * Wentworth Miller as Leonard Snart/Captain Cold
 * John Barrowman as Arthur King/Merlyn
 * Tom Ellis as Sebastian Ballesteros/Cheetah
 * Gal Gadot as Diana Prince/Wonder Woman
 * Jesse Eisenberg as Lex Luthor
 * Katie Cassidy as Dinah Lance/Black Canary
 * Grant Gustin as Barry Allen/the Flash
 * Melissa Benoist as Kara Danvers/Supergirl
 * Chris Wood as Mike Matthews/Mon-El

Guest Starring

 * Neil Patrick Harris as the Music Meister (Special Guest Star)

Trivia

 * This episode achieved 14.78 million U.S. live viewers.
 * Alexander Gould and Wentworth Miller do not appear in this episode as Dick Grayson and Leonard Snart.
 * This episode received generally positive reviews. It scored 67% on Rotten Tomatoes, a 76 out of 100 on Metacritic, and 8.1/10 on IGN.
 * Guest stars in this episode include Neil Patrick Harris as the Music Meister
 * This episode is rated TV-PG for L.

Songs

 * The Music Meister
 * Succeed
 * If Only
 * This is a Rescue
 * The World is Mine
 * Off to Work