Supergirl scored well in the overnight ratings for "Medusa."
Preview clip for the Supergirl episode "Medusa" featuring Mon-El vs. Cyborg Superman
Preview clip for the Supergirl episode "Medusa" which kicks off the DC TV crossover.
Preview images for the Supergirl episode "Medusa" featuring the return of Helen Slater as Eliza Danvers
Official CW description for the Supergirl episode "Medusa" guest starring Helen Slater