Sheldon and Amy's honeymoon runs aground in New York.

Amy and Sheldon can't figure out their wedding gifts.

Penny and Leonard's marriage is put to the test.

Sheldon's childhood friend, Tam, visits.

Sheldon sabotages Amy's career.

Howard dresses up as Sheldon for Halloween.

Leonard regrets his newfound authority at work.

Raj and Anu have trouble making things physical.

Sheldon and Amy's scientific theory hits a wall.

Sheldon seeks advice from his younger self.

The truth comes out on the paintball field.

Penny's ex-boyfriend asks Leonard for a huge favour.

A rival team of physicists tries to take credit for Super Asymmetry.

Sheldon must choose between his friends or following the rules.

Penny tries to divert Leonard's plans to be a sperm donor.

The guys try to crash Wil Wheaton's celebrity D&D game.

Sheldon wants to experiment on Howard's kids.

Amy and Sheldon try to win over Nobel laureates.

The weight of winning a Nobel weighs heavy on Amy.

Penny encourages Leonard to stand up for himself.

Amy and Sheldon try to take the high road for the Nobel Prize.

Leonard's mother is finally nice to him.

Sheldon and Amy await big news.

In the series finale, the gang travels together into an uncharted future.