Whip together TV's The Invaders and V. Fold in cult classic ENEMY FROM SPACE and season with a dash of SPECIES. The yield: an agreeable cocktail of paranoid sci-fi conventions that bubbles along energetically, despite surprisingly low-tech trappings (an underground complex here, a little alien morphing there... nothing that shifts the focus from scary bedtime story to F/X spectacular). Granted, fleshy bully-boy Charlie Sheen strains credulity as whiz-kid radio astronomer Zane Ziminski, but costars Lindsay Crouse and Ron Silver (as, respectively, a flinty scientist and a bureaucratic sleaze) display satisfactory acting chops. There's a creepy xenophobic subtext (unintentional, we suppose, but why do those evil aliens come from Mexico?), a knockout suspense sequence involving a hotel room full of scorpions and, as a bonus, the niftiest little lethal sphere since PHANTASM.