Navy Lt. Commander Calvin Lee is found hanging from a bridge.

This happens just as he was due to ship out as executive officer aboard a submarine equipped with advanced technology, raising suspicions at NCIS.

Callen, Sam and the rest of the NCIS agents must determine whether he committed suicide or was murdered and what, if anything, has been compromised.

When Calvin’s parents were questioned, they claimed they had two children, but that Calvin’s older sister died. Not the case.

The team had to dig to find out the sister was actually living under a new name.

More interestingly, she told them that Calvin, whom his parents said was engaged to marry a woman, was actually homosexual.

Tracking down Calvin’s fiancee led the team to a Chinese spy ring that was trying to force Calvin to sneak a high-tech hard drive cloner aboard his sub.

The fiancee was a handler trying to keep an eye on Calvin, who was being groomed as a spy from day one.

Calvin ultimately decided to kill himself rather than obeying his handlers, and threw a cloner, disguised as a set of keys, off the bridge.

Callen and Sam did not realize the cloner was in the keys until they began to ponder how the missing Dom might approach this case.

In the climax, Kensi tried to sneak Calvin’s parents out of their store before they could be killed by Chinese agents.

Callen and Sam meanwhile tried to neutralize the various agents in a crowded marketplace.

We learn that Calvin’s parents were forced to raise him to be a Chinese spy ensconced in the U.S. military. But he didn't go for it.