Soviet sleeper agents? Hidden nuclear bombs? These are cold war myths, right? 

Sam and Callen thought both were things of legend until they uncovered the secret left by former CIA agent, Frank Turner. He killed himself to protect the secret and trusted the investigation to Sam.

"Out of the Past, Part I" started out as one of the most bizarre NCIS: Los Angeles episodes ever. From the preview, I thought we were going to learn about Sam's home life, but that will have to wait for another day.

Sam showed up to find Turner hanging from the ceiling from an apparent suicide. And that's when the mystery started to get weird. Why was the power turned off and the door busted open? And why did Turner have a poodle?

The investigation led the team to Megan Hendley, a flight attendant that was really a CIA agent and Turner's lover. She set the team on the right track. Turner was investigating the Sinclair Project and looking for Soviet sleeper spies.

I was sucked in right from the beginning from the mysterious death, to the conspiracy against Turner, to the ticker tape code in Turner's stomach, to the dog show, to Robert Pierce's parents. It was a well-written mysterious thriller. 

The poodle and the dog show provided a little comedy relief from an otherwise dangerous and intense investigation. Kensi even got in a nice ass grab on Deeks when he was hiding the microchip reader. A dog whisperer, Deeks is not!

What started as a look into old-school spies became a serious and extremely dangerous situation when Mr. Pierce showed Sam and Callen the bomb he had been hiding for decades. This was not a small suitcase bomb, but a huge bomb. One that would be more destructive than the one dropped on Hiroshima if detonated.

The picture became clear. Turner had the fail safe call go to Sam because he could not only put the pieces together, but knew the target from the task force they were on together. An arms dealer was hunting down Turner to find out the identities of the sleeper agents, so he could take the nuclear bombs and sell them.

A terrorist's dream - a nuclear bomb that is already on US soil. These bombs would be worth a lot of money to the right person. And, they are each in a heavily populated area. At least NCIS has the list, if they can get to the bombs before anyone else, they will protect the nation.

Turner was a patriot. He killed himself rather than risk being tortured to give up the names. He picked the right person as his fail safe. Sam and the team were able to figure it out despite the multiple layers of manual encryption.

The only downside to the episode is that we have to wait two weeks for the conclusion. The build up was a thriller, I can only imagine how action-packed the second part will be.

Carla Day is a staff writer for TV Fanatic. Follow her on Twitter and on Google+.