TNT's 'Librarians' question their institution in season 4

There are more adventures ahead for "The Librarians" as Season 4 of the TNT fantasy series opens this week. But the biggest challenge may come from the library itself.

Last season, the library became untethered and thus no longer grounded to humanity, and so in an elaborate ceremony in the Wednesday, Dec. 13, season opener, Baird and Flynn (Rebecca Romijn, Noah Wyle) step up to make the sacrifice that will tether them to the library forever and make them immortal.

Or so it would appear.

"It's a beautiful wedding. It's quite scintillating," reports John Harlan Kim, who plays one of the librarians, master thief and tech expert Ezekiel. "It's sort of this idea - or at least that's what it looks like - that the four corners of the map all have something to do with the upcoming season. Obviously, it all centers around the tethering ceremony and what that means, not just for Flynn and Baird, but for the rest of the librarians.

"And you sort of start to see the effect and the pressure of being a librarian," the Australian actor continues. "And you end up sort of seeing the disagreement between the team about where they stand on certain issues and it kind of almost reflects a regular family where not all members of the family are going to have the same viewpoints on things and whether they're going to agree all the time. But at the end of the day, they are a family and you're going to see them sort of work through it together."

The new season sees Ezekiel, Baird, Cassandra (Lindy Booth) and Stone (Christian Kane) embarking on more adventures protecting the world from the magical reality hidden all around. They'll be facing off against Santa's brother the Patron Saint of Thieves, saving a town haunted by ghosts from the Civil War, taking on a casino that steals luck and undoing a body-switching fiasco involving one of the librarians.

That last storyline, a stand-alone episode that will air later in the season, marks Booth's directorial debut. For this, the Canadian actress took lots of notes at the side of co-star Wyle, an experienced director and one of the series' executive producers, who she praises for his generosity and for making it "an incredible experience."

"I love working on this show because anything is possible with magic," Booth says, "and so we are never bored with our show because every episode is a different episode. And especially this season, I think we really jump all over the place with genres and it's a lot of fun for us as actors but I think also for the audience because we deal with so many different subjects and so many different tones.

"And so the body-swap episode is really fun," she continues. "It's definitely one of our stand-alone, sort of like fun episodes this year. And yeah, we have someone from the library switches places with someone else, and hilarity and confusion and drama and danger ensue."