J’onn Tells Kara & Alex He’s Going to Mars in “Supergirl” Sneak Peek

The CW has released a sneak peek for episode #303 of Supergirl, which you can check out below. The installment, titled “Far From the Tree,” is officially described as follows:

CARLOS BERNARD (“24”) GUEST STARS; HELEN SLATER RETURNS

Eliza (guest star Helen Slater) throws Alex (Chyler Leigh) and Maggie (guest star Floriana Lima) a wedding shower, which causes Maggie to reach out to her estranged father (guest star Carlos Bernard). Supergirl (Melissa Benoist) joins J’onn (David Harewood) on a personal mission.

Supergirl, “Far From the Tree,” was directed by Dermott Downs and by written by Jessica Queller & Derek Simon. The episode airs Monday, October 23, at 8pm on The CW.