Lisbon accepts Jane’s surprise marriage proposal, but a killer’s quest for revenge may cost them the happy ending they’ve worked so hard to achieve.

The Heck family learns about Darrin’s marriage proposal to Sue…as well as her response. Meanwhile, Axl attempts to use his intro to Psych class to cure Brick of all of his quirks and tics.

Malcolm puts Oliver and Thea in a dangerous situation that lands them on Lian Yu with Oliver’s former enemy, Deathstroke. A flashback reveals when Oliver and Maseo returned to Starling City to retrieve the Omega bio weapon, and despite being under strict orders from Amanda Waller not to reveal himself to anyone, Oliver looks in on his family, Laurel and Tommy.

Peggy is cornered and more vulnerable than ever as Leviathan makes their move against her. As the SSR zeroes in on Howard Stark, they may pay the ultimate price as they find their true enemy is closer than they realized.

After the nuclear explosion separates Ronnie and Dr. Stein, Barry and the team believe both men are safe. Caitlin is thrilled to have her fiancé back and prepares to resume their life together while Dr. Stein returns to his wife. When General Eiling targets Firestorm, Ronnie and Dr. Stein must decide if they are safer together or apart. Mason Bridge tells Iris that there is something secretive going on at S.T.A.R. Labs. Dr. Stein gives Barry some important information about time travel.

Jimmy pulls out all the stops to prove that his dangerous client is innocent, even though it causes some friction with Kim.

Jimmy pulls out all the stops to prove that his dangerous client is innocent, even though it causes some friction with Kim.

In the second installment of the Castle two-parter, stakes rise as the 12th Precinct matches wits with serial killers Jerry Tyson (3XK) and Dr. Kelly Nieman. With the clock ticking, Castle and the team must crack the case before the killers claim their next victim.

When the new partnership with Ellis reaches a boiling point, Marty and the Pod hatch a new plan with Gage Motors, intent on hitting an even bigger payday. Jeannie seriously considers an attractive job offer. Roscoe cuts school to party with his new friends.

Harvey and Louis take a drive to aid an out-­of-town client to whom they both have deep ties; and Harvey uses the opportunity to force a confrontation between Louis and Mike about their trust issues. Meanwhile, in a flashback, we discover the root of Harvey and Louis’s competitive relationship in their early days at the firm. And Mike first learns the limitations of his genius when it comes to the law.