Barry must deal with the Reverse Flash’s latest threat to a member of the group. To make matter worse, Dr. Wells unleashes Grodd on the city in order to distract Barry and the team. Joe, Barry and Cisco head down into the sewers to catch Grodd but the gorilla quickly gets the upper hand after he kidnaps Joe. Iris and Barry have a heart to heart talk.
When a clever clever con man, Professor DeSalvo, uses his class to cheat the study group, they enlist Jeff to get revenge. The situation goes awry as Britta and Dean Pelton get involved in Jeff and Professor DeSalvo’s scamming competition.
When Sid Ross, the powerful creator of a long-running sketch comedy show is killed, Castle and Beckett are called to investigate. But as they delve into the victim’s life and the colorful world of “Saturday Night Tonight,” they uncover a shocking secret that may explain Sid’s murder.
When a former client calls Alicia after being charged with murder tied to a case from 2009, Alicia reviews the old case, prompting memories of her early days as a lawyer.
The Faith Militant grow increasingly aggressive. Jaime and Bronn head south. Ellaria and the Sand Snakes vow vengeance.
Leda and Castor are both on the hunt for original clone DNA. On-the-lam, Mark and Gracie pursue new leads to find the samples that might set them free, while Art and Sarah reunite to track them down. Meanwhile, Cosima and Scott try to learn more about Castor’s biology and Alison’s new money-making venture is going gangbusters. A shocking revelation about the Castor-Leda connection leaves the sisters reeling, just before Sarah witnesses a deadly Prolethean-Castor face-off.
Phil and Jay run an errand together to pick up Lily’s hand me down princess castle for Joe, both though are in a mood because Phil is upset that Claire won’t let him buy an arcade machine, and Jay thinks Gloria is letting Joe play with too many girlie items. Mitch and Cam babysit Joe and both get the itch for another baby – that is until Joe presents to be quite the handful! Meanwhile, Gloria tries to help Haley stand up for herself at work, and Claire tries to bribe Luke’s principal to give him one of the student awards this year.
Frankie and Mike struggle to stay awake when watching a movie during a cozy date night at home. Meanwhile, a handsome mall employee asks Sue to her senior prom and Axl and Brick hope to find success with a barbecue sauce they’ve created.
Oliver goes through a rigorous transformation. The League of Assassins sets their sights on Nyssa, who is back in Starling City training Laurel. When Nyssa realizes they are coming, she arms up to face them alone but Laurel asks Felicity and Diggle to help protect her new friend.
Gonzales and Coulson must find a way to put their differences aside and work together against Hydra, even if it means teaming up with someone they don’t trust.