Callen's hair is making a comeback on NCIS: Los Angeles.

'NCIS: LA' Season 7 Premiere Plot Revealed; Callen's Lone Wolf Mission Puts Sam On High Alert

The lead agent usually sports a close-cropped look, but undercover missions occasionally cause G (Chris O'Donnell) to grow out his buzz cut. Set photos for episode 702 (airing order unconfirmed) show Callen's prison look will return in early season 7.

 Brian L Smith capturing my inner karate kid for season 7 #ncisla

A photo posted by chrisodonnell (@chrisodonnell) on Aug 11, 2015 at 5:49pm PDT

It is currently unknown why Callen will give his razor a break. It could, however, have to do with the events of the premiere. Check out a summary for "Active Measures":

'NCIS: LA' Season 7 Spoilers: Talia Del Campo Is Back! Mercedes Mason & Eric Christian Olsen Goof Off In New PHOTOS

"The seventh season premieres with Callen embarking on a secret project, leaving Sam and the entire team in the dark," CBS teased. "After Hetty (Linda Hunt) demands his operation be shut down, the team is tasked with locating Callen before he finds himself in over his head."

Will this lone wolf act have to do with G's search for his father? Last Callen heard, his father was six-feet under. The series-long mystery won't end that easily, however, or at least that's what the season 6 finale sting wants us to think.

Find out more when NCIS: LA returns to CBS on Sept. 1 at 10 p.m. ET.