LOS ANGELES, Jan. 8 (UPI) -- Summer Glau will guest star on Castle Season 8.
Glau and Fillion co-starred as Malcolm Reynolds and River Tam on Fox series Firefly and the feature film Serenity. The pair previously reunited for Episodes 1 and 7 of the actor's web series Con Man with fellow co-star Alan Tudyk.
Firefly ran for just one season, but maintains a following among fans. The sci-fi series, which follows the exploits of the Serenity spaceship crew, was created by Joss Whedon, and former stars Adam Baldwin and Gina Torres have also appeared on Castle.
Castle will return from mid-season break Feb. 1. The crime drama follows Castle, a best-selling mystery novel author, as he helps detective Kate Beckett (Stana Katic) solve cases. Fillion and Katic won Favorite TV Crime Drama Actor and Actress at the 2016 People's Choice Awards on Wednesday.
Glau has starred on a number of series since Firefly, including Whedon show Dollhouse, Alphas and Arrow. She last played Anna Brandt on the Crackle series Sequestered, which co-starred Jesse Bradford.