'The Librarians' season 3 episode 9 spoilers: Black ninjas threaten the balance of the universe in season's penultimate episode

Cassandra's (Lindy Booth) tumor has been removed, and contrary to what she initially feared, the operation did not at all interfere with her Librarian abilities. If anything, it even seems to have enhanced it.

This twist could not have come at a better time, seeing as "The Librarians" is about to hit this season's penultimate episode. In season 3 episode 9, which is titled "The Librarians and the Fatal Separation," the balance of the Universe is put on the line when a merciless collector of magical artifacts threatens Shangri-La, the sacred homeland of the Monkey King.

Based on the trailer for the next episode, the Librarians will be called upon to form a united front against the enemy, which seems to be comprised of black ninjas, with the ultimate goal of saving the imperiled land from doom. Their selfless heroism, however, may just come at a very terrible cost that could, in turn, threaten their own lives.

Will Cassandra's newfound ability let itself be known in the middle of an intense combat that is about to come up? Will it work to their advantage, or will it threaten Cassandra's life once again with unknown consequences to its use?

In an interview with Entertainment Weekly following last Sunday's "The Librarians" episode, Booth shared her initial concerns about bringing Cassandra's tumor to the forefront once again in what she described as a "lighthearted and goofy show." She commended the writers for having done a good job of showing Cassandra's struggle through the stages of grief with an option of immortality dangling in her mind.

"The way that we get to see her processing it was a really, just a beautiful roadmap, and a very simple way of portraying a very complex emotion," Booth said.

Now that the tumor is gone, Cassandra can begin to live a more centered life and focus on the things that lie ahead. She can also fully commit to her duties as a Librarian now, which could prove crucial going into the final episodes of the season.

Additionally, even though Jenkins (John Larroquette) has gently turned down her affections, Cassandra seems to have found one other potential partner in Estrella (Clara Lago), the vampire she met at the wellness spa. Booth described the relationship as "beautiful" but did offer any information on whether her character will be pursuing this relationship in the future.

"There's a beautiful thought there, that this is a person who looked at Cassandra and didn't see her gift or weirdness," Booth shared. "That's probably the first time that's really happened to Cassandra, and so that relationship is really special and beautiful."

"The Librarians" season 3 episode 9 airs on Sunday, Jan. 15, at 8 p.m. EST on TNT.