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

Chuck and Sarah put aside spy work to have a weekend of debauchery, but Awesome’s plans for Chuck’s big night don’t go quite as expected. Meanwhile, Ellie's investigation into her father's computer leads to a life-changing discovery.

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.