After this week's episode, which was primarily lighter fare, NCIS raises the stakes big time next Tuesday with the return of Special Agent E.J. Barrett (Sarah Jane Morris).

Introduced several weeks ago as both a love interest for Tony and a rival for Gibbs, those two components will complicate matters for the mysterious E.J. in "Two-Faced."

When Barrett returns to lead an investigation of a death that may be connected to a series of murders - triggering the port-to-port killer story line - tensions with Gibbs rise.

Also intriguing? Vance's role in all this.

The Director always plays it close to the vest, but he's clashed with Gibbs more lately than ever before, especially after their recent blowup over the interrogation incident.

Did he bring Barrett in to say on (or unseat) Jethro in some fashion? Why is a separate team assembling in D.C.? Does Vance have an endgame we've yet to understand?

What do you think? Do you trust Vance?

What his role is in the serial killer story arc is unclear, but it will be interesting to see play out. Follow the jump for CBS promo for "Two-Faced" and comment below ...

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.