Supergirl and team must stop Nyxly from vanquishing a familiar face from Supergirl's past - Mr. Mxyzptlk. Mxy returns and explains Nyxly's dark history to the super team in the best way he knows how - in song form. Meanwhile, Lena visits her mother's birthplace in Newfoundland, eager to dig into her past but is shocked by the small town's icy reception towards her.
Elenco: Melissa Benoist , Chyler Leigh , David Harewood , Mehcad Brooks , Jeremy Jordan , Katie McGrath , Chris Wood , Jesse Rath , Nicole Maines , Odette Annable , Floriana Lima , Calista Flockhart , Andrea Brooks , Azie Tesfai , Julie Gonzalo , Staz Nair .