Mxy is back, and he's ready to sing a tale about Nyxly's past, in order to help Supergirl and the team to stop her. It seems that at least part of Nyxly's plan is to vanquish Mxy, so he has a stake in the game in order to help. Meanwhile, Lena is on the hunt for more information on her mother's past in Ireland, but doesn't find that the townspeople are all receptive to her entrance, which makes this expedition that much harder for her. Check out the full synopsis below:
THOMAS LENNON RETURNS AS MR. MXYZPTLK – Supergirl (Melissa Benoist) and team must stop Nyxly (Peta Sergeant) from vanquishing a familiar face from Supergirl’s past – Mr. Mxyzptlk (guest star Thomas Lennon). Mxy returns and explains Nyxly’s dark history to the super team in the best way he knows how – in song form. Meanwhile, Lena (Katie McGrath) visits her mother’s birthplace in Ireland, eager to dig into her past but is shocked by the small town’s icy reception towards her. The episode was directed by Glen Winter with story by Rob Wright and teleplay by Elle Lipson & Chandler Smidt (#611). Original airdate 9/14/2021.