Brody meets Homeland Security agent John Russo (guest star Ivan Sergei) on Tuesday's episode, "Help Wanted," while she's in Washington, D.C., tracking down a lead in the Navy lieutenant leak case. As we already know, NCIS partners with Homeland Security to track down a bunch of missing explosives.
So that's why John is involved. But here's a question: Could he also be the mole who's going to be exposed in the finale? The episode is called "Sleeping with the Enemy," after all. And McLellen told TVGuide.com earlier this year that Brody is about to exhibit some "reckless" behavior. When we asked executive producer Gary Glasberg to elaborate, he admitted: "I'm guessing this is what she's referring to."
(Full disclosure: TVGuide.com is owned by CBS.)