Valentine’s Day aims its sights on the Heck kids when a nervous Brick finds out that his quirky girlfriend Cindy wants him to kiss her on the special day, Darrin asks Frankie and Mike to help out with an exciting scavenger hunt he’s putting together for Sue, and Axl begins to question his girlfriend Devin’s request that he not give her anything for what she considers to be a lame tradition.
Peggy discovers the shocking truth about Leviathan but doesn’t realize that her true enemies are even closer than she imagined. Meanwhile, Sousa is close to confirming the truth about Peggy and may just put her in the crosshairs of the SSR.
After Ronnie attacks a physicist, Barry and the team realize they need to go after Caitlin’s fiancé who is now a dangerous meta-human. Barry struggles to balance his duties as The Flash and his relationship with Linda Park. Joe enlists Cisco’s help to reinvestigate the murder of Nora Allen. General Eiling returns to Central City.
When clues in a murder implicate Castle and Beckett’s nemesis, Dr. Kelly Nieman, Castle is called in to consult on the case.
As his troubles escalate to a boiling point, Jimmy finds himself in dire straits. An act of carelessness puts Chuck at risk.
Jimmy works his magic in the courtroom. Unexpected inspiration leads him to an unconventional pursuit of potential clients.
When the partnership between Ellis and Maya reaches a boiling point, Marty devises a plan that Jeannie opposes. Clyde develops feelings for Kelsey as they seek investors for their start-up.
Harvard ethics professor Henry Gerard seeks Harvey’s help with a case that requires a lack of ethics to win. Mike, meanwhile, does his best to not be spotted by the professor, whose class he never took; and Louis tries to wine and dine a socialite CEO.
Bellamy and Lincoln’s attempt to sneak into Mount Weather has brutal consequences. Abby fights to stay in control as Clarke steps up in her new leadership role. Meanwhile, with Monty and Harper still missing, a desperate Jasper confronts President Wallace and demands answers.
Phil starts to feel the teenage cold shoulder from Luke and, with Andy hanging around a lot as his apprentice, he easily steps in as his new right hand man. Gloria and the doctors suspect that Joe might be allergic to Stella. Mitchell does some freelance legal work at Jay’s closet company and working with Claire becomes a very enlightening experience for the both of them.