Kara teams up with her cousin to stop a new threat in National City. A kryptonian pod comes crashing down to Earth.
Cadmus attacks National City with a kryptonite powered villain who attempts to seriously hurt Supergirl.
Lena is arrested when Metallo breaks Lillian out of prison and evidence suggests that she is responsible, Kara fights to clear Lena's name, and Alex introduces Maggie to the gang.
