The November 28 episode of "Supergirl," titled "Medusa," will serve as a lead-in to The CW crossover event "Invasion!" which sees the Arrowverse come together to take on the invading alien threat of the Dominators, and new images reveal how Kara Danvers is recruited into the superhero team-up.

RELATED: New Supergirl Synopsis Previews Start of CW Superhero Crossover

While "Medusa" is not fully a part of the larger crossover story, images show Barry Allen and Cisco Ramon visiting Kara's Earth to ask for her help in fighting the Dominators. Other images introduce Kara and Alex's mother, Eliza, inspecting a sickly-looking Mon-El, and Hank Henshaw/Martian Manhunter having a serious conversation with Supergirl.

Supergirl -- Medusa -- Image SPG208a_0019 -- Pictured (L-R): Melissa Benoist as Kara/Supergirl and David Harewood as Hank Henshaw -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208a_0019 -- Pictured (L-R): Melissa Benoist as Kara/Supergirl and David Harewood as Hank Henshaw -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208a_0054 -- Pictured(L-R): Melissa Benoist as Kara/Supergirl and David Harewood as Hank Henshaw -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208a_0054 -- Pictured(L-R): Melissa Benoist as Kara/Supergirl and David Harewood as Hank Henshaw -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208a_0082 -- Pictured(L-R): Melissa Benoist as Kara/Supergirl, Helen Slater as Eliza Danvers, David Harewood as Hank Henshaw and Chyler Leigh as Alex Danvers -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208a_0082 -- Pictured(L-R): Melissa Benoist as Kara/Supergirl, Helen Slater as Eliza Danvers, David Harewood as Hank Henshaw and Chyler Leigh as Alex Danvers -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208a_0086 -- Pictured(L-R): David Harewood as Hank Henshaw, and Chyler Leigh as Alex Danvers -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208a_0086 -- Pictured(L-R): David Harewood as Hank Henshaw, and Chyler Leigh as Alex Danvers -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208a_0111 -- Pictured: Chris Wood as Mike/Mon-El -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208a_0111 -- Pictured: Chris Wood as Mike/Mon-El -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208a_0113 -- Pictured: Helen Slater as Eliza Danvers -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208a_0113 -- Pictured: Helen Slater as Eliza Danvers -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208a_0120 -- Pictured(L-R): Melissa Benoist as Kara/Supergirl, Jeremy Jordan as Winn Schott, and David Harewood as Hank Henshaw -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208a_0120 -- Pictured(L-R): Melissa Benoist as Kara/Supergirl, Jeremy Jordan as Winn Schott, and David Harewood as Hank Henshaw -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208b_0008.jpg -- Pictured (L-R): Melissa Benoist as Kara/Supergirl and Grant Gustin as Barry Allen -- Photo: Bettina Strauss /The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208b_0008.jpg -- Pictured (L-R): Melissa Benoist as Kara/Supergirl and Grant Gustin as Barry Allen -- Photo: Bettina Strauss /The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208b_0014.jpg -- Pictured (L-R): Melissa Benoist as Kara/Supergirl, Grant Gustin as Barry Allen and Carlos Valdes as Cisco Ramon -- Photo: Bettina Strauss /The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208b_0014.jpg -- Pictured (L-R): Melissa Benoist as Kara/Supergirl, Grant Gustin as Barry Allen and Carlos Valdes as Cisco Ramon -- Photo: Bettina Strauss /The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208b_0028.jpg -- Pictured (L-R): Grant Gustin as Barry Allen and Melissa Benoist as Kara/Supergirl -- Photo: Bettina Strauss /The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208b_0028.jpg -- Pictured (L-R): Grant Gustin as Barry Allen and Melissa Benoist as Kara/Supergirl -- Photo: Bettina Strauss /The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208b_0064 -- Pictured: Melissa Benoist as Kara/Supergirl -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208b_0064 -- Pictured: Melissa Benoist as Kara/Supergirl -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208b_0093 -- Pictured(L-R): Melissa Benoist as Kara/Supergirl, Chyler Leigh as Alex Danvers, David Harewood as Hank Henshaw, and Helen Slater as Eliza Danvers -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208b_0093 -- Pictured(L-R): Melissa Benoist as Kara/Supergirl, Chyler Leigh as Alex Danvers, David Harewood as Hank Henshaw, and Helen Slater as Eliza Danvers -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208b_0128 -- Pictured(L-R): Chris Wood as Mike/Mon-El, Melissa Benoist as Kara/Supergirl, Chyler Leigh as Alex Danvers, David Harewood as Hank Henshaw, and Helen Slater as Eliza Danvers -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208b_0128 -- Pictured(L-R): Chris Wood as Mike/Mon-El, Melissa Benoist as Kara/Supergirl, Chyler Leigh as Alex Danvers, David Harewood as Hank Henshaw, and Helen Slater as Eliza Danvers -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- Medusa -- Image SPG208b_0143 -- Pictured(L-R): Chris Wood as Mike/Mon-El and Melissa Benoist as Kara/Supergirl -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved
Supergirl -- "Medusa" -- Image SPG208b_0143 -- Pictured(L-R): Chris Wood as Mike/Mon-El and Melissa Benoist as Kara/Supergirl -- Photo: Bettina Strauss/The CW -- © 2016 The CW Network, LLC. All Rights Reserved

A NIGHT OF CONFESSIONS; THE EPIC SUPERHERO CROSSOVER KICKS OFF TONIGHT — Eliza (guest star Helen Slater) comes to town to celebrate Thanksgiving with her daughters. Alex (Chyler Leigh) decides it’s time to come out to her mother; Kara (Melisa Benoist) is shocked when Eliza suggests Mon-El (Chris Wood) has feelings for her, and Winn (Jeremy Jordan) and James (Mehcad Brooks) consider telling Kara the truth about the Guardian. Meanwhile, CADMUS unleashes a virus that instantly kills any alien in the vicinity so Kara enlists an unexpected ally – Lena Luthor (Katie McGrath). The epic superhero crossover kicks off tonight when Barry Allen (guest star Grant Gustin) and Cisco Ramon (guest star Carlos Valdes) seek Kara’s help with an alien invasion on their Earth. Stefan Pleszczynski directed the episode written by Jessica Queller & Derek Simon (#208). Original airdate 11/28/2016.

The crossover begins Monday, Nov. 28, on the midseason finale of “Supergirl,” and continues Tuesday, Nov. 29, on “The Flash” and Wednesday, Nov. 30, on “Arrow” before concluding Thursday, Dec. 1, on “DC’s Legends of Tomorrow.”