'Supergirl' season 2 episode 8 spoilers: DC Week kicks off with family dinner, killer virus and alien invasion

The "Heroes v Aliens" crossover event is happening on The CW next week. But before it does, "Supergirl" has a few personal wrinkles to iron out first as one Thanksgiving evening opens up opportunities for some life-changing confessions.

In the episode titled "Medusa," Eliza (Helen Slater) comes over to celebrate the happy occasion with her daughters and their friends. While James (Mehcad Brooks) and Winn (Jeremy Jordan) try to muster up the courage to tell Kara aka Supergirl (Melissa Benoist) the truth about the Guardian, Alex (Chyler Leigh) has already made up her mind to come out to her mom.

Considering how Eliza quickly notices Mon-El's (Chris Wood) feelings for her adoptive daughter Kara within just moments of knowing him, could she have already known about Alex? How will these impending revelations affect their Thanksgiving dinner? Will J'onn (David Harewood) be there as well and would he consider telling everyone his gradual and inevitable transformation into a white Martian?

Cadmus is also stirring up some trouble as they unleash a deadly virus that could instantly end the life of any alien within its immediate vicinity. This conflict once again brings Supergirl and Lena (Katie McGrath) into an alliance against the Luthor matriarch, Lillian (Brenda Strong).

In a recent interview with Entertainment Weekly, actress Strong shared that while Lena does not yet know about her mother's involvement with Cadmus, the younger Luthor starts figuring things out about her mother's nefarious plans in next week's episode. This supposedly impacts their relationship in some way.

The much awaited epic superhero team-up begins when Barry (Grant Gustin) and Cisco (Carlos Valdes) cross over into Kara's world to enlist Supergirl's help in fighting off an alien race threatening to invade their Earth.

The official trailer shows Supergirl meeting up with everyone and taking quite an interest in Heat Wave's rather "colorful backstory."

How does Supergirl's addition affect an already established team rapport between the Earth-1 heroes? Does her usually perky mood annoy some of the more serious heroes, or does her presence serve as an inspiration for everyone to harness powerful forces they didn't even know they have?

The world's fate is in the hands of the biggest superhero team-up happening in DC Week starting off with "Supergirl" on Monday, Nov. 28; "The Flash" on Tuesday, Nov. 29; "Arrow" on Wednesday, Nov. 30; and "Legends of Tomorrow" on Thursday, Dec. 1. All shows air at 8 p.m. EST on The CW.