Supergirl -- "City of Lost Children" -- SPG220a_0002.jpg -- Pictured: Lonnie Chavis as Marcus and Mehcad Brooks as James Olsen/Guardian -- Photo: Bettina Strauss/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220a_0072.jpg ñ Pictured (L-R): Lonnie Chavis as Marcus and Mehcad Brooks as James Olsen/Guardian -- Photo: Bettina Strauss/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220a_0083.jpg ñ Pictured (L-R): Lonnie Chavis as Marcus and Mehcad Brooks as James Olsen/Guardian -- Photo: Bettina Strauss/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220a_0266.jpg ñ Pictured (L-R): Lonnie Chavis as Marcus and Mehcad Brooks as James Olsen/Guardian -- Photo: Bettina Strauss/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220a_ 333.jpg ñ Pictured: Lonnie Chavis as Marcus -- Photo: Bettina Strauss/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220a_ 349.jpg ñ Pictured: Lonnie Chavis as Marcus -- Photo: Bettina Strauss/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220b_0027.jpg ñ Pictured (L-R): Chris Wood as Mike/Mon-El, Melissa Benoist as Kara/Supergirl, and David Harewood as Hank Henshaw -- Photo: Dean Buscher/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220b_0035.jpg -- Pictured: Chris Wood as Mike/Mon-El -- Photo: Dean Buscher/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220b_0086.jpg ñ Pictured: Teri Hatcher as Rhea -- Photo: Dean Buscher/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220b_0577.jpg ñ Pictured: Teri Hatcher as Rhea -- Photo: Dean Buscher/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220b_0601.jpg ñ Pictured: Teri Hatcher as Rhea -- Photo: Dean Buscher/The CW -- © 2017 The CW Network, LLC. All Rights Reserved

Supergirl -- "City of Lost Children" -- SPG220b_0719.jpg ñ Pictured (L-R): Teri Hatcher as Rhea and Chris Wood as Mike/Mon-El -- Photo: Dean Buscher/The CW -- © 2017 The CW Network, LLC. All Rights Reserved