A brooding novel that pits the Secret Service and computer programmers against an unknowable future, Big If certainly has timing on its side. But like the bureaucrats and detached code writers he characterizes, author Mark Costello slowly loses control of his own plans. Focusing on a sister-brother pair who follow different career paths to similarly despondent ends, Big If opens with a moving remembrance of New Hampshire family life. As children, unmotivated Vi Asplund and her engineering-prodigy brother Jens travel from town to town with their father, a pragmatic insurance adjuster whose job entails making sense of senseless disaster. Moving into adulthood, both siblings work to fend off the incomprehensibleVi as a Secret Service agent protecting the vice-president, Jens as an analytical programmer for a web-based war game called BigIf. At the start, Costello does an exquisite job of weaving his lead characters' parallel tales together. But Big If falls fatefully off balance when Vi and Jens cease to be lead characters, winding up as mere recurring figures drowned out by stories of their coworkers' equally tattered lives. Toiling with Vi in the Secret Service "protectoracy" are a bunch of overworked feds trained to investigate arcane leads and scan cheering crowds for the guns that might kill them. Jens' compatriots at BigIf approach their work with a similar sense of paranoia, bracing against the realization that their programming, however elegant and ingenious, translates into farting monsters in a video game whose popularity is waning. Digging into the systematic yearnings and anxious fatalism of both worlds, Costello occasionally cooks up a chilly tension worthy of Don DeLillo. He's funny, too, shaping farcical details like a D.C. lingerie boutique called Inside The Beltway, and a Secret Service agent placing bets on a Palmolive-Rachmaninoff piano competition. But quips and atmospherics are little compensation for a static plot that never develops beyond exposition. There seems to be an epochal novel lurking somewhere in Big If, but as the story strains for universal reach, its initial focus grows as elusive as the forces that weigh so heavily on the characters' minds.