|Season 4, Episode 4|
|War Is Coming||Panic Button|
BRAINIAC LIVES- A captive Lucy Lane and Astra In-Ze discover that Brainiac is being experimented on by the military. James Olsen and Karen Starr combat a government assassin sent to eliminate Guardian.
- Melissa Benoist as Kara Danvers/Supergirl
- Chyler Leigh as Alex Danvers
- Jeremy Jordan as Winslow Schott
- Katie McGrath as Lena Luthor
- Laura Benanti as Astra In-Ze
- Zachary Quinto as General Dru-Zod
- Tyler Hoechlin as Kal-El
- Odette Annable as Reign
- Floriana Lima as Maggie Danvers (credit only)
- Jenna Dewan as Lucy Lane
- with Claire Holt as Karen Starr/Power Girl
- Mehcad Brooks as James Olsen/Guardian
Special Guest StarEdit
- Jon Cryer as Lex Luthor
- Lauren German as President Veronica Banks
- Glenn Morshower as General Sam Lane
- Brenda Strong as Lillian Luthor
- Amy Acker as Brainiac
- Minka Kelly as Lois Lane
- with Katheryn Winnick as D.I.S.C.O.R.D.
- and Dianna Agron as Major Raya Zod-El
- Harry Shum, Jr. as Jonathan Drew/Assassin
- Antagonists: Sam Lane, Lillian Luthor, D.I.S.C.O.R.D., Lex Luthor
- This episode is Lucy-centric.
- Maggie does not appear in this episode.
- This episode is set on July 3, 2020.
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