"High School Musical" alum Corbin Bleu will guest star in "Castle" Season 8 as Hunter Washington who will be involved in a case that the Cas-Kett will investigate. Co-showrunner Alexi Hawley shared some details about the upcoming episode entitled "Tone Death" where ABC released its official plot description.

"High School Musical" star Corbin Bleu officially signs in to guest star in the upcoming episode of "Castle" Season 8. According to Christian Post, the 26-year-old Jamaican-American actor will be playing the role of Hunter Washington, the leader of the rival a capella group that will be involved in a murder that the couple will be investigating next. Bleu's character is slated to debut in the "Tone Death" episode.

In addition, co-showrunner Alexi Hawley has discussed with TV Line that Rick and Kate have lost a lot of time to make up for in the previous episodes. Because of that, Hawley teased that fans should expect some sweet and intimate Cas-Kett moments in the upcoming episodes.

Aside from the a capella case, the couple will also enter a courtroom for the very first time in the series. Hawley also revealed to the outlet that fans will actually see a trial based on a case where Castle will be testifying in court.

As for the official synopsis of episode 9, Spoilers Guide notes, "When a body is found in the theater of Martha Rodgers' (Susan Sullivan) latest show, best-selling mystery novelist Richard Edgar "Rick" Castle (Nathan Fillion) and NYPD homicide detective Katherine Houghton "Kate" Beckett's (Stana Katic) investigation leads them into the unexpectedly dangerous world of competitive a capella."

"Castle" Season 8 returns with its 9th episode entitled as "Tone Death" on Monday, February 8. 2016 at 10:00 p.m. exclusively on ABC.

"Castle" is an American crime drama created by Andrew W. Marlowe which follows the lives of Rick Castle and Kate Beckett.