"NCIS: Los Angeles" Season 6 is coming to a close, but before the team goes on a hiatus, they are making sure to leave fans with the best season finale yet.

While last week's episode was intense, that was nothing compared to what will be shown in the upcoming episode. Episode 23 is titled "Kolcheck, A.," which pertains to a man that Sam and Callen must find. Arkady Kolcheck is connected to a missing oil tanker whose crew has been massacred. Only Arkady may hold the key to the mystery.

The official synopsis goes:

"Callen and Sam will search for answers when they find dead crew members from the missing oil tanker used in Arkady's deal with Russia, and also discover Arkady's personal connection to the ship."

Given that this episode will be a season finale, the story won't just revolve around solving the mystery. According to the other spoilers, Callen will discover surprising information about his father. But what's more surprising is actor Eric Christian Olsen's revelations about what the season finale will be.

Cliffhangers aren't really something new when it comes to season finale episodes, which just makes sense because the show wants to keep the audience interested as to what the next story will be. However, Olsen told Yahoo! that in this particular season finale, it was "the most brutal and terrifying cliffhanger I've ever seen for hour-long television."

"I didn't know how they were going to shoot it, how they were gonna do it. Because I read it on the page and we (lead stars) were calling each other, 'Are they serious about this?'" Olsen added.

Olsen spilled that the finale will show Callen and Kensi going to Iran, while Deeks and Hannah work together. Deek's wife will be involved and will be in danger.

As for his relationship, this is what Olsen had to say, ""The season Finale is incredible...is terrifying...brings that relationship to a crescendo... something happens, it's catastrophic and it all falls apart."

"NCIS: Los Angeles" Season Finale will air on May 18 on CBS.