Perseus shield. Perseus then proceeded to the Gorgons' cave. In the cave he came upon the sleeping Medusa. By viewing Medusa's reflection in his polished shield, he safely approached and cut off her head. From her neck sprang Pegasus ("he who sprang") and Chrysaor ("sword of gold"), the result of Poseidon and Medusa's mating. The other two Gorgons pursued Perseus, but, wearing his helm of darkness, he escaped. From here he proceeded to visit King Atlas who had refused him hospitality; in revenge Perseus turned him to stone. On the way back to Seriphos Island, Perseus stopped in the kingdom of
Medusa (Supergirl) is raising suspicions about her. Hank Henshaw plants a device that unleashes smoke at the bar, which kills all the aliens inside except for Mon-El. Mon-El is placed in isolation and Eliza is brought in to figure out the toxin. The virus consumes Mon-El before Eliza determines it is Kryptonian. Kara determines Cadmus needed her blood so Henshaw could break into the Fortress of Solitude. Kelex regards Kara as an intruder and attacks; she learns Henshaw accessed the file on Medusa, a virus created for defense against potential invaders by her father. Eliza affirms her support for Alex coming out.