In the third episode of Season 13 of "NCIS," Bishop and McGee go undercover as man and wife in hopes of learning more about a mysterious marine lieutenant and his wife.

CarterMatt reports the two crew members' longtime friendship is put to the test as they take on the challenges of a married pair. The website adds at one point the two find the need to share a kiss. Later, Bishop embarks on a solo journey that causes everyone to worry.

The previous episode was highlighted by McGee (Sean Murray) and Bishop (Emily Wickersham) growing sentimental as they tried to figure out why the-still-recuperating Gibbs (Mark Harmon) has changed as much as he has following his life-threatening experience.

The episode also featured the arrival of a DEA agent named Luis, who asked for the team's help in reigning in a suspected drug lord named Benson Long.

After becoming part of the case, Agent DiNozzo (Michael Weatherly) instantly wondered why Gibbs seemed to be willing to go to any lengths to aid the agent. He later learned that Luis is the son of the agent who died trying to protect his family and shared the information with both McGhee and Bishop.

All the intrigue and mystery only boiled more when McGhee shot someone described as "a person of interest," all in a desperate effort to protect Luis.

In time, Bishop discovered that Benson was the one who ordered the hit on Gibbs' family. Still, Gibbs stopped Luis from killing Benson, who was later forced to confess to ordering the slayings of both their families.

Showrunner Gary Glasberg recently told TV Guide viewers will learn all sorts of things about Gibbs this season that they never knew before.

Added Weatherly, "I think what we're going to have this year is a fundamental shift in the show and that's a fascinating thing to see. I don't want to give away too much, but I think the audience will respond with great interest to some of the tonal changes."