NCIS: Los Angeles fans are currently caught up in a swarm of new developments but will have a chance to step back later this season in order to solve an old mystery- what's in the box?

"The Box" first appeared during season 4's "Kill House." It showed up on Kensi's (Daniela Ruah) desk and, being the overly curious person he is, LAPD liaison Marty Deeks (Eric Christian Olsen) was eager to discover what was inside.

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As it turned out, the package was a birthday gift for Deeks, albeit a bit delayed. However, after saying the gift was in the giving, Deeks put the box aside and never opened it. Now that the show is well into its fifth season, the infamous box is still sitting in the background of the NCIS headquarters.

Luckily for fans, both Olsen and series creator Shane Brennan have stated that the mystery of the box will be addressed later this season.

"I can tell you that later in the season, [Deeks] takes the box down and puts it on his desk and stands over it and he may or may not open it," Brennan told TV Fanatic.

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Olsen also spoke to TV Fanatic about his character's renewed interest in the package.

"[Viewers are] going to have to wait," Olsen said when asked if the box would be opened early in the season. "I think it's gonna be this season. We'll find out what's in the box."

Some fans have likened the box to a metaphor for the Densi relationship and, considering the pair is set to undergo shocking revelations and some time apart courtesy of this year's episodes 10 and 18, perhaps the contents of the box will be linked to the partner's changing dynamic.

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Meanwhile, for those wondering about the fate of Deeks' doppelganger aquarium, executive producer John Peter Kousakis tweeted that it too will be resurfacing.

NCIS: LA airs Tuesdays at 9 p.m. ET on CBS.