NCIS is racing towards an epic two-part conclusion to the current season which will see the agents take on a terrifying new threat.

Agents Tim McGee (played by Sean Murray) and Alden Parker (Gary Cole) are on the case next week for the start of NCIS season 20’s explosive finale.

The latest promo has teased a gripping murder case at the centre of a Russian conspiracy.

Meanwhile, the new romance between Dr Jimmy Palmer (Brian Dietzen) and Jessica Knight (Katrina Law) could be about to hit its first speed bump.

A synopsis for the upcoming episode, Kompromat, reads: “When a suspicious murder occurs in the classified section of the National Archive, NCIS must investigate a string of Russian spy encounters that may be linked to the crime.

“Also, Jimmy accidentally makes a confession that could change the course of his relationship with Knight.”

The trailer kicks off with the victim in question lying in a pool of blood in the National Archive.

Palmer spots a deep stab wound under the armpit while McGee investigates a pile of top secret files on the floor.

“Looks like our killer was doing some research on Russia,” he reveals.

Parker later meets with NCIS Director Leon Vance (Rocky Carroll) to discuss the mission at hand.

“If the Russians are planning something big…” he begins, before Vance confirms: “It’ll be up to us alone to stop it.”

The promo concludes with a shot of McGee and Parker entering a room with firearms at the ready.

However, fellow agents Nicolas Torres (Wilmer Valderrama) and Knight’s roles in the mission are currently unknown.

NCIS rarely treats viewers to two-parters outside of the recent crossover episodes with NCIS: Los Angeles and NCIS: Hawaii.

Whatever the series is planning for the next two weeks could be huge, with plenty of unexpected twists for the agents.

The two-parter is confirmed to kick off with Torres behind bars while the rest of the team stops a terror attack.

Hopefully he has a plan up his sleeve and hasn’t simply gone rogue, but NCIS fans have learned to expect the unexpected when it comes to the hot-headed agent.

Could the Russian scheme feature the return of a major returning villain or perhaps set up a new nemesis for Parker and the team?

And could Dr Palmer’s confession bring his relationship with Knight to an end?

This month will also feature the conclusion of beloved long-running spin-off NCIS: LA, but thankfully more seasons of NCIS: Hawaii and the mainline drama are in the works.

NCIS season 20 continues Mondays on CBS in the USA. A UK release date is yet to be announced.