Spoiler alert: The following article contains spoilers from Will Trent season 3, episode 17, "Why Hello, Sheriff."

Although Will Trent's main characters have largely stayed the same, with Will Trent, Angie Polaski, Faith Mitchell, Amanda Wagner, and Michael Ormewood being at the center of the show's story since season 1. Now, one new figure is shaking things up at the end of season 3.

ABC will release the Will Trent season 3 finale, "Listening to a Heartbeat," on Tuesday, May 13, at 8 pm ET.

The good news is that ABC has already renewed Will Trent for a fourth season. Its renewal doesn't come as a surprise, though, since the series has been such a success for the network throughout its first three seasons. Will Trent continues to triumph in the ratings (and to receive great reviews), thanks to its complex characters, shocking developments, and intriguing stories. With the addition of one new cast member, season 4 will likely follow suit.

Will Learns Who His Biological Father Is In Will Trent Season 3, Episode 17

Will's Father Isn't James Ulster

In a shocking turn of events, Will finally learns who his birth father is in Will Trent season 3, episode 17, "Why Hello, Sheriff," and it's not James Ulster. The crime drama previously led fans to believe that Ulster, a serial killer who murdered Will's mother, was his father. The series never explicitly stated that Ulster was one of Will's biological parents, but the criminal insisted that he was. Now, though, we know that's not the truth.

In Will Trent season 3's penultimate hour, Will and his partner, Faith Mitchell, meet a cold, small-town sheriff named Caleb Roussard (played by Yul Vazquez, known for his role as Petey in Severance) when assigned to one of his cases. Caleb makes it clear that he thinks very little of the GBI, and, at first, it seems like the show is setting him up to be a villain. However, everything changes when Will learns that Caleb is his biological father.

Still, Caleb makes an effort with Will, who initially doesn't want anything to do with him, but that will probably change as time goes on.

At the crime scene, Will shuts a glass door too forcefully, causing glass to shatter everywhere. The shards cut Will, Faith, Caleb, and another deputy. So, the forensics team is forced to differentiate their blood from the victims'. When the test results come back, Pete (the medical examiner) discovers that Will and Caleb are related, stunning Ramón Rodríguez's Will Trent character. It also surprises Caleb, who, all this time, had no idea he had a son. Still, Caleb makes an effort with Will, who initially doesn't want anything to do with him, but that will probably change as time goes on.

Yul Vazquez Is Set To Have A Recurring Role In Will Trent

Vazquez Should Return In Will Trent Season 4

Prior to the release of Will Trent season 3, episode 17, TVLine announced that Yul Vazquez would have a "major recurring role" in the show. Unfortunately, the outlet didn't confirm that Vazquez would reprise his role as Caleb in season 4. However, given that the mystery of who Will's birth parents are has hung over the ABC police procedural since the beginning, it would only make sense that the protagonist's newly discovered father returns in future episodes.

Plus, Vazquez's Will Trent role was labeled as "major." Someone who only appears in two episodes before disappearing from a TV show forever probably wouldn't be considered a significant character. So, it's only right that the Severance star returns in Will Trent season 4.

How Season 4 Can Continue Will & Caleb's Story

There Is Much To Unpack When It Comes To Will & Caleb's Relationship

With so much going on in the Will Trent season 3 finale (including possible character deaths), the last episode likely won't have much time for Will and Caleb. They'll be too busy contending with the bioterrorism attack to have many deep discussions about their situation. Consequently, season 4 should focus on developing Will and Caleb's relationship.

Will might have a hard time letting his biological father in, given his trauma growing up and Caleb's ignorance of Will's existence. But they have many things to bond over, including their careers. Caleb is also seemingly determined to get to know his son, no matter how long it takes for Will to trust him. Of course, the events of the Will Trent season 3 finale will determine what's to come, meaning they could easily affect how season 4 approaches Will and Caleb's story.

Source: TVLine