The search for Seeley Booth (David Boreanaz) begins next month when "Bones" returns for season 11. 

Earlier spoilers revealed that Booth will mysteriously disappear in the premiere episode titled "The Loyalty in the Lie." And the latest update claims that in the same episode, the team will have to solve one of the biggest cases they have ever encountered. 

According to the episode synopsis, Booth and his wife Brennan (Emily Deschanel) have already fulfilled their dreams of living a calmer, safer life with their daughter Christine and their newborn son, away from the chaotic crime-busting life. This happens several months after they decided to quit their jobs at the Jeffersonian Institute Medico-Legal Lab and the FBI. 

But a new case that has a strong personal connection with the couple requires Brennan to return to the lab to work in the forensic analysis of a dead body. Booth, on the other hand, mysteriously disappears. This is why an extensive FBI investigation has to be launched to find him. 

FBI Agent James Aubrey, Booth's former protégé and the successor to his old post, along with Agent Grace Miller (guest star Kim Raver from "24") investigate the former agent's sudden disappearance. But tensions arise when Miller's investigation centers on one of the members of the team, who she believes is the primary suspect in Booth's sudden disappearance. The team is allegedly irked with Miller's method of investigation, which tends to ignore protocol. 

Booth's absence from the show was actually due to Boreanaz needing some time off. The actor earlier admitted that he suffered from a bad antibiotic reaction back in summer, so the producers of the long-running crime-procedural comedy-drama came up with the plot wherein his character mysteriously disappears.   

In an interview with TVLine in late August, Boreanaz said, "Nothing matters to me more than Bones, so I was thrilled when the producers came up with a way for me to take a few extra weeks to recover from a personal health issue without delaying production." 

After recovering, Boreanaz immediately went back to work to tape the remaining episodes for the season.

"Bones" season 11 premieres on Thursday, Oct. 1, on FOX.