Chuck encourages Vivian to get in touch with her inner villain for a mission. Morgan's search for a new roommate has unexpected results.

With the help of his old nemesis Alexei Volkoff, Chuck and the team hunt down a deadly weapon, The Norseman. In a pre-wedding surprise, Sarah springs a pre-nup on Chuck.

Chuck and Sarah’s wedding prep includes one final detail: ensuring that the mother-of-the-groom makes it to the ceremony alive. Meanwhile, Morgan’s responsibilities as Best Man include his most dangerous mission yet, as he faces Vivian Volkoff. Elsewhere, Ellie tends to the last details of the rehearsal dinner and seeks help from an unlikely source.

Before he can kiss the bride, Chuck must enlist his wedding party to take down Vivian Volkoff and stop her from destroying the big day. When he turns to Alexei Volkoff for help, the CIA sends its toughest agent, Clyde Decker, to stop them.