Abby enlists Dan on a quest to find a girl's letter to Santa, Gurgs' gift for Dan isn't what she expected, and a witness believes herself to be the Ghost of Christmas Present.

It's Christmas Eve and Johnny wants to celebrate with an old-fashioned Rose Christmas Party but the rest of the family has trouble getting into the holiday spirit.

It’s the holiday season at St. Denis. Alex and Ron care for a patient whose diagnosis is not what it seems. Joyce enlists Serena’s help to boost St. Denis’ online presence. Bruce and Matt help a Santa in need.

Leonard asks a woman out after he finds out that Penny is seeing someone.

With his friends knowing how sour he acts when he’s sick, Sheldon is nursed by Penny, who hasn't got a clue what she's in for.

A Christmas visit from his mother has Leonard discovering she's kept a lot of news from him that she shares with Sheldon and worrying if she'll approve of his romance with Penny.

During a game, Sheldon revisits Christmas memories. Amy, Penny and Bernadette look for a date for Koothrappali.

Amy starts working at Caltech which causes friction with Sheldon. Howard agrees with Sheldon who mentions this to Bernadette causing a big fight for the Wolowitzes.

Amy forces Sheldon to celebrate a Victorian Christmas.

When Leonard and Penny fight, Sheldon plays the unlikely peacemaker. Meanwhile, Howard and Raj try to fix a squeaky floorboard in the baby's room

Christine attends her neighborhood Christmas party where she learns a juicy secret about her neighbor.

Alan starts dating a woman with a Martha Stewart complex. Before long she's running the house with an obsession for perfection.

Charlie's friends and family put a crimp in his plan for a romantic Christmas Eve date. When Evelyn sees who the date is, she goes to great lengths to force a wedge between them.

Alan is unhappy about his sex-life with his new girlfriend Donna and breaks up with her. Charlie helps a now-free Jake hit on a girl while the two are out dining but it ends up with Charlie getting pepper sprayed.

Charlie helps Jake cheat on his girlfriend while she's away for the holidays and Evelyn brings a television producer to Charlie's Christmas dinner.

Walden's mother visits, dropping a secret about him as well as leaving Alan smitten.

Still pretending to be the poverty-stricken "Sam Wilson", Walden spends Christmas with Kate. Meanwhile, Walden & Billy close a deal to sell their electronic suitcase for $1.2 billion. Elsewhere, Alan's Christmas goes south when all his loved ones have other commitments.

Walden helps Jenny get a second date with a one-night stand.

It's Caroline's first broke holiday season and, to earn extra money, she and Max apply to work as elves at a department store's "Santaland".

Caroline and Max decide to apply for a loan so they can mass-produce their T-shirt idea.

Caroline tries to embrace Bobby's hobby of bowling, but she fears she is his bad luck charm when she injures his teammate's hand threatening their chance for a championship.

Mike tries to find the perfect Christmas gift for Molly.

Disappointment at work threatens to ruin Molly's Christmas.

Mike worries over Molly's Christmas spending habits.

Mike struggles to be home for Christmas.

Abby enlists Dan on a quest to find a girl's letter to Santa, Gurgs' gift for Dan isn't what she expected, and a witness believes herself to be the Ghost of Christmas Present.

It's Christmas Eve and Johnny wants to celebrate with an old-fashioned Rose Christmas Party but the rest of the family has trouble getting into the holiday spirit.

It’s the holiday season at St. Denis. Alex and Ron care for a patient whose diagnosis is not what it seems. Joyce enlists Serena’s help to boost St. Denis’ online presence. Bruce and Matt help a Santa in need.

Leonard asks a woman out after he finds out that Penny is seeing someone.

With his friends knowing how sour he acts when he’s sick, Sheldon is nursed by Penny, who hasn't got a clue what she's in for.

A Christmas visit from his mother has Leonard discovering she's kept a lot of news from him that she shares with Sheldon and worrying if she'll approve of his romance with Penny.

During a game, Sheldon revisits Christmas memories. Amy, Penny and Bernadette look for a date for Koothrappali.

Amy starts working at Caltech which causes friction with Sheldon. Howard agrees with Sheldon who mentions this to Bernadette causing a big fight for the Wolowitzes.

Amy forces Sheldon to celebrate a Victorian Christmas.

When Leonard and Penny fight, Sheldon plays the unlikely peacemaker. Meanwhile, Howard and Raj try to fix a squeaky floorboard in the baby's room

Christine attends her neighborhood Christmas party where she learns a juicy secret about her neighbor.

Alan starts dating a woman with a Martha Stewart complex. Before long she's running the house with an obsession for perfection.

Charlie's friends and family put a crimp in his plan for a romantic Christmas Eve date. When Evelyn sees who the date is, she goes to great lengths to force a wedge between them.

Alan is unhappy about his sex-life with his new girlfriend Donna and breaks up with her. Charlie helps a now-free Jake hit on a girl while the two are out dining but it ends up with Charlie getting pepper sprayed.

Charlie helps Jake cheat on his girlfriend while she's away for the holidays and Evelyn brings a television producer to Charlie's Christmas dinner.

Walden's mother visits, dropping a secret about him as well as leaving Alan smitten.

Still pretending to be the poverty-stricken "Sam Wilson", Walden spends Christmas with Kate. Meanwhile, Walden & Billy close a deal to sell their electronic suitcase for $1.2 billion. Elsewhere, Alan's Christmas goes south when all his loved ones have other commitments.

Walden helps Jenny get a second date with a one-night stand.

It's Caroline's first broke holiday season and, to earn extra money, she and Max apply to work as elves at a department store's "Santaland".

Caroline and Max decide to apply for a loan so they can mass-produce their T-shirt idea.

Caroline tries to embrace Bobby's hobby of bowling, but she fears she is his bad luck charm when she injures his teammate's hand threatening their chance for a championship.

Mike tries to find the perfect Christmas gift for Molly.

Disappointment at work threatens to ruin Molly's Christmas.

Mike worries over Molly's Christmas spending habits.

Mike struggles to be home for Christmas.

Abby enlists Dan on a quest to find a girl's letter to Santa, Gurgs' gift for Dan isn't what she expected, and a witness believes herself to be the Ghost of Christmas Present.

It's Christmas Eve and Johnny wants to celebrate with an old-fashioned Rose Christmas Party but the rest of the family has trouble getting into the holiday spirit.

It’s the holiday season at St. Denis. Alex and Ron care for a patient whose diagnosis is not what it seems. Joyce enlists Serena’s help to boost St. Denis’ online presence. Bruce and Matt help a Santa in need.

Matty’s unorthodox Christmas wish is granted, completely upending the Bennett family dynamic. A trip to church gets John and Ted wondering about Ted’s miraculous origin.