The Big Bang Theory – Season 4, Episode 16

PGR Penny finds herself along for the ride on Sheldon's first ever date. Meanwhile, Wolowitz finds a new use for a robotic arm.

G When Sheldon realises he won't live long enough to download his consciousness into a robot body, he attempts to extend his lifespan.

G The guys are concerned as Sheldon searches for an alternative to human companionship after he and Amy break up.

PGR An embarrassing secret of Howard's comes to light, while Sheldon and Raj have a small war at work.

G Leonard realises he's the only one without a girlfriend, while Sheldon wants to get rid of his.

G A visit from Raj's sister creates tension among the guys - especially when Leonard keeps an affair secret from them.

G When an FBI agent interviews the guys for Wolowitz's security clearance, Sheldon's answers put Wolowitz's freedom in jeopardy. Guest starring Eliza Dushku.

PGR When the guys camp in line for a screening, their plans are thwarted by Sheldon's greatest nemesis. Guest starring Wil Wheaton.

PGR Penny pulls Leonard into a lie when her dad comes to visit.

G Amy finds she has feelings for Penny's ex-boyfriend, while Koothrappali and Wolowitz try to prove who would be the better superhero.