'Castle' season 8 episode 14 spoilers: Firefly's Summer Glau is in; Castle recruited by Greatest Detective Society

Stana Katic in 'Castle' Season 8 — Actress Stana Katic arrives at the 2015 Film Independent Spirit Awards in Santa Monica, California February 21, 2015. Reuters/Danny Moloshok

In Season 8 Episode 14 of “Castle,” Richard Castle (Nathan Fillion) will be dealing with the Greatest Detective Society for a murder case. There will also be a couple of guest stars including Summer Glau, according to reports.

Spoiler alert: This article contains “Castle” season 8 spoilers. Read on if you would like to know what happens next before the new episode airs.

In the previous episode, titled “And Justice For All,” Castle had to go undercover as a French Canadian to get more details about a student who was murdered.

The next episode, titled “G.D.S.,” which stands for “Greatest Detective Society,” will also be an opportunity to watch Summer Glau, who has been requested by several fans for some time now, writes TV Line. Glau is set to reprise her role as Kendall Frost, a provocative private detective in Los Angeles who will compete with Castle in attempting to solve the deadly mystery.

Gerald McRaney will also guest star as Mason Wood, leader of the Greatest Detective Society. Most likely, Beckett will also have a part in the investigation, since there does not seem to be a lot of things for the other regular cast members in the episode.

Glau and Fillion will be working again after they previously collaborated in one episode of “Con Man.” The two were also together in “Firefly.” Glau is the third alum of “Firefly” to guest star in at least one episode of “Castle” with Fillion. The two others who previously guest starred are Gina Torres and Adam Baldwin.

Glau previously appeared in TV shows like “Arrow,” “The Sarah Connor Chronicles,” “Alphas” and “Dollhouse.”

Considering Glau’s comic tendencies, the upcoming episode is expected to be funny. Fans will have to watch to see how the story can link both the comedy and seriousness of the murder case.

“Castle returns to the City of Angels in search of answers about his missing time. But things take a deadly turn when he’s recruited by the legendary Greatest Detective Society to help solve a murder,” the official episode synopsis stated.

Season 8 Episode 14 of “Castle” will air next on Mar. 7 on ABC. The episode was directed by John Terlesky and written by Alexi Hawley. More updates and details are expected soon.

Here’s a sneak peak into “The G.D.S.”