At the secret base under the froyo shop, Shaw brings Sarah a cup of cappuccino and a straw to chew on. Shaw tells the team that he thinks the Mask of Alexander is being used to smuggle something by the Ring. Shaw informs Sarah that she will pose as his date at the party. Chuck insists they bring Hannah to the mission since she can help with the technical aspects of the party.

Morgan meets with Ellie and tells her that Chuck is rarely at work. Morgan says he thinks Chuck went to a dark place after Sarah dumped him.

Chuck has Hannah pack at the Buy More while Shaw goes over a checklist of equipment with Sarah at the base. Shaw tells Sarah they should figure out their cover story. Sarah insists they haven't slept with each other in their cover.

Outside the party, Casey waits out in his van while watching surveillance. Inside, the curator asks Chuck and Hannah to prevent any crashes or bugs. While Shaw caresses Sarah's neck, he asks her to scope out the area.

Hannah tells Chuck the real reason she took the job was because of him. She gives him a kiss, then notices that Sarah is at the party. She asks her if he is over Sarah, then notices that Sarah is with a date. Chuck flashes after he notices a man who has a record of theft and trafficking. Chuck runs to the party and identifies the Ring agent who stole the mask, Damascus Vasillis. Shaw says Vasillis might recognize him since he met him in the past. Hannah watches as Sarah tells Shaw to leave while she takes care of the situation with Chuck.

While Chuck and Sarah sneak into a room, Chuck sets off a virus in the control room. Hannah works on fixing the problem while Sarah and Chuck dress into their gear. Casey cuts off their mikes while Chuck shares his jealousy over her relationship with Shaw. Sarah tells Chuck that Hannah can't get her hands off him.

Sarah enters the vault while Vasillis sends his men in. After a man punches Chuck, he falls into the vault, but is held up by the line attached to Sarah. Sarah is able to take out the man, but is attacked by another. Back in the control room, Hannah is able to open the vault door, but Shaw hacks in and closes it. After Sarah takes out the other man, she drops Chuck the fake mask to switch it. Chuck barely manages to escape just before Hannah opens the door to unveil the mask.

Chuck goes to the control room and apologizes to Hannah for leaving. She says she is upset that he abandoned her and figures he was with Sarah. Chuck explains he has an unique relationship with Sarah. Hannah says she regrets kissing him, then leaves.