The Grid

TNT's first episodic offering since the comic-book drama ''Witchblade'' focuses on a different type of superhero: The four-part thriller follows NSA operative Maren Jackson (''ER'''s Julianna Margulies) and FBI agent Max Canary (''The Practice'''s Dylan McDermott) as they travel from London to New York City to the Middle East to dismantle a terror cell. ''What I was most impressed about,'' says McDermott, ''was that it was told in a 'Traffic'-esque way -- the Arabs had their view and the CIA had theirs.''

Margulies, meanwhile, did some serious homework to prepare for her jargon-heavy role. ''Our executive producer came with files and files of Pentagon stuff that I could look at and immediately give back,'' she says. ''And I watched CNN around the clock.''

The challenges weren't entirely academic for McDermott, who developed new respect for the FBI one night in Toronto. ''It was 40 below and I was climbing a ship at midnight on a rope -- over and over again. I thought, 'These FBI guys [really] have to do this.''' Yeah, but usually only once.

WHY WE'LL TUNE IN As the former stars of established shows, McDermott and Margulies are enough of a draw. But add ''Grid'''s topical premise and the promise of intricate storytelling, and it may be one of summer's most thrilling series.