The Red Scare - A life is on the line as the team chases Flynn to Washington, D.C., during the Red Scare of the 1950s in the Season 1 finale. Also: The trio attempt to take down Rittenhouse once and for all; and Lucy wagers the ultimate sacrifice to save history.
EPICSHELTER - The recruits learn what to do if they're ever exposed; and a death leads to an FBI investigation at the Farm. In the future, Alex returns to the crisis zone and exposes the traitor.
Neighborhood Watch - Kevin concocts an elaborate plan to avoid spending time with Donna's cousin and her chatty husband by forming a neighborhood watch group with his buddies.
Mr. & Mrs. Mxyzptlk - A magical imp named Mr. Mxyzptlk shows up on Earth and declares his love for Kara, who tries to let him down easy. However, he won't take no for an answer and starts to wreak havoc on National City. As Mon-El and Kara argue over how to get rid of Mr. Mxyzptlk, Alex and Maggie celebrate their first Valentine's Day together.
3: 00 PM-4: 00 PM - Grimes finds new information that could lead to the terrorists and passes it along to Carter. Elsewhere: Rebecca sequesters and questions Nilaa at the Donovan compound.