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 Ireland, eager to dig into her past but is shocked by the small town's icy reception towards her.

Supergirl and team race Nyxly for control of a magical totem that controls courage. Supergirl and Nyxly battle and each get a piece of the totem but learn the first person to pass the test of courage will gain control of the entire thing. Meanwhile, Lena is still struggling to make sense of her newfound gift.