Every time it looks as if NCIS: Los Angeles' Deeks and Kensi are going to finally get together, another stumbling block is thrown in their way.

The last two minutes of this week's "Recovery" had Densi fans holding their breath. While Kensi (Daniela Ruah) is still driven slightly insane by Deeks' (Eric Christian Olsen) inability to ever say what he means, viewers still don't know exactly what happened after the LAPD Detective said he would rather be home with her than out to dinner.

'NCIS: LA' Season 5 Spoilers: Major Densi Scene In 'Recovery;' Will Deeks and Kensi Split Up in 'Frozen Lake?' VIDEO

However, the partners are in for a bit of a shake up in the upcoming episode "Frozen Lake." The "dynamic [and] enigmatic" installment will "test the heart of our series," according to director and executive producer John Peter Kousakis.

"Kensi and Deeks face their biggest challenge, both professionally and personally in coming episodes," said series creator Shane Brennan, according to TV Line. "The emotional ripple that started with their unexpected kiss at the end of last season is about to turn into a tsunami that doesn't just impact them, but the whole team. As a result, one of them will be reassigned."

It's fairly safe to say that the reassignment refers to Kensi's seven-episode jaunt in Afghanistan; it's a bit more difficult to determine what will fuel her departure.

'NCIS: LA' Season 5 Spoilers: First Look at Major Densi Episode PHOTO, Details on Game Changing Deeks, Kensi 'Frozen Lake' VIDEO

While Hetty (Linda Hunt) has fretted about the Deeks and Kensi's dynamic before, a new promo (see below) makes it appear as if the partners' inability to keep their feelings separate from their work may put someone in danger and cause enough of a disruption that the two are temporarily separated.

NCIS: LA airs Tuesdays at 9 p.m. on the CW.