Detective Marty Deeks may often hide his emotions behind a joking façade, but recent events will eventually take their toll on the NCIS: Los Angeles character.

When viewers last saw Deeks (Eric Christian Olsen), he was unwillingly having a bit of dental work done by Siderov (Timothy V. Murphy) following Marcel Janvier (Christopher Lambert) betrayal of the special projects team. When season 5 premieres with "Ascension," Deeks will have to deal with the fallout from the events of "Descent."

"I think we're going to see the most human reaction we've ever seen on this show to something like this," Olsen told Entertainment Weekly. "I think a lot of times these things happen and there aren't any emotional consequences and there are unbelievable emotional consequences. I don't think he's prepared to compartmentalize it. I don't know if he knows how to get through it...this is going to have a very real, long-lasting effect on him."

However, Deeks has more than just the trauma of torture to deal with. The LAPD Detective took a risk the last time he saw his partner Kensi (Daniela Ruah), putting his feelings for her out in the open. Now the pair must finally deal with the consequences of their budding relationship.

"It's the best premiere we've ever had," Olsen claimed, according to Entertainment Weekly. "We have the most honest scene we've ever seen between Kensi and Deeks."

Take a glance at some behind the scene photos from the first week of shooting here and find out what viewers can expect from Deeks this season here.

NCIS: LA returns to CBS on Sept. 24 at 9 p.m.

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