These days, The X-Files is busy with babies and more cast changes than a hardcore conspiracy theorist could handle. Gone, with little explanation, is our beloved Fox Mulder (real-life reason: David Duchovny finally extricated himself from his old contract). Barely present is our beloved Dana Scully (real-life reason: Gillian Anderson is merely fulfilling the final season of her contract). Meanwhile, the guy who was supposed to fill Mulder's fed-issued brogans, Agent John Doggett, has been relegated to lurking in the background (real-life reason: Beats me. Robert Patrick is as hard-boiled and effective as ever), and shoved to the forefront is Agent Monica Reyes (a ferocious yet lissome Annabeth Gish), who's catching up on years of X-File mythology. As if the credits weren't crowded enough, Cary Elwes, best known for his dashing role in the 1987 film ''The Princess Bride,'' has come aboard as an FBI investigator who once did some bed wrestling with Reyes but who now may be her enemy.''The X-Files'' operates in what now seems like quaint territory, searching for alien invaders colluding with a government splinter group to control -- oh, I dunno, does anyone besides creator Chris Carter? -- the world, I presume. But its atmosphere of free-floating anxiety jibes with this moment in history. Just as Scully isn't sure whether her newborn child is infected with alien DNA, so do many of us fear infection by foreign spores. And the man we most want to get in Afghanistan is as difficult to grasp as the solution to a thick, yellowing X-File, filled with a history of foreboding and death.