A bad day compels Penny to re-evaluate her choices — including Leonard; Bernadette and Howard must care for Mrs. Wolowitz; Sheldon gives Raj advice on relationships.
Amy and Sheldon's relationship takes a surprising turn during a game of "Dungeons & Dragons;" Lucy and Koothrappali have an awkward date.
When NASA moves up Howard's mission, he must face his fears and Bernadette's dad, thus putting the wedding plans in jeopardy. Meanwhile, Leonard says something surprising to Penny in the bedroom.
When Howard finally breaks the news to his mom that he's engaged to Bernadette, it lands her in the hospital.
While Penny worries that dating Leonard has ruined her for normal guys, Wolowitz and Koothrappali search for Sheldon's perfect match online.
The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.
L and the Task Force close in on Higuchi who continues to play into their hands. But as time before Kira's identity is revealed on Sakura TV gets closer, Higuchi gets desperate and makes the deal for shinigami eyes.