Artifacts include the "Spruce Goose" aircraft, a T-Rex skeleton, President William McKinley's torn nightshirt, empty picture frames from an art heist, a watch from the Johnstown flood, and the invention of the Slinky.
When George gets credit for one of Jim's secret crime-fighting activities, animosity breaks out between the two friends. Meanwhile, Daphne suspects something is wrong with Katie's new boyfriend, JJ discovers a problem with his powers, and Stephanie and Katie disagree over a personal matter.
Carter can't get into the Christmas spirit especially with the town surrounded by a force-field. Fargo organizes the GD holiday party, and Allison is full of holiday cheer.
Mike works with a falconer to chase birds away. Then Mike butchers a cow from the hoof clear through to steaks.
As the Warehouse team prepares to celebrate the holidays in snowy South Dakota, Pete and Myka are called upon to hunt down a malevolent Santa Claus. Meanwhile, in time for Hanukkah, Artie and his estranged father, Isadore Weisfelt reunite after 30 years.
The men battle feral hogs, and experts are called in to help; and Billy and Ricky rescue an injured baby bunny.
Lux and Tasha are forced to deal with the fallout of their recent actions and the potential outcome could change the course of both their lives. As a result, Lux can no longer hide her past from Cate and Baze.
Adrianna rents a mansion and decides to throw a housewarming party complete with an ice skating rink and elves. All is great in Adrianna's world until Victor decides to reveal Adrianna's secrets to the media. Annie decides to skip the party so she can take care of Liam, which leads to the two of them rekindling their old romance in Dixon's bed. Ivy's reconciliation with her father doesn't go quite as she planned. Teddy and Ian discuss their feelings and decide to keep their relationship quiet for the time being, unaware that Dixon saw them share a kiss. Meanwhile, Navid and Silver share their feelings and realize they both feel the same way. Naomi returns home from the party to find an unexpected visitor.
It's Christmas Eve and someone is calling in on the Umi Alarm from far away. It's Santa Claus!
Liam is a taxi driver who is bored with everyday life and is desperate to escape it. One day Emma gets into his cab and he falls deeply and madly in love with her, he starts to dream that he can be everything she needs in life.
Mike allows Carl to bring a date to his apartment, so he decides to spend some time at Molly's house where he actually manages to bond with Molly's mother and sister.
One of Brenda's detectives is ambushed on the street, and the main clue to figuring out the motive behind the attack is a garbage bag containing more than $37,500. The investigation then turns into a race to clear the detective's name over allegations of witness tampering.
Castle and Beckett investigate the murder of a dockworker turned bar owner who's body is found floating in the East River. In the process of the investigation they uncover a secret buried since the days of Prohibition.
While picking in Pennsylvania, Danielle sends the guys to Bushkill Park–a century-old amusement park that’s seen much better days. Hoping to eventually renovate and reopen, owner Neil is motivated to sell just about anything. And, after stepping back in time and playing in the old funhouse, Mike spies a couple of rare vintage sideshow banners. Also in this episode… Deb wants husband Tom to clear out his sprawling collections so they can enjoy their retirement on the road in their RV. But he’s reluctant to sell his prized possessions. Later, in New York City, the guys meet an expert who has shocking news about Mike’s new circus posters. In Staten Island, a cavernous abandoned storage unit yields plenty of carnival keepsakes.
Alan goes to great lengths to be able to get Lyndsey a nice birthday present.
Don realises he still has feelings for Sam after hearing of Brian's intention to propose.
When Ted's new friendship with Zoey tests the theory that single men and married women can't be friends, he invites her husband, "The Captain," to hang out with them. Meanwhile, Marshall and Robin decide to spend alone time together, and Barney and Lily possibly have a fight.