By Jennifer Reese
Updated August 08, 2003 at 04:00 AM EDT

It’s 1961, just weeks before the erection of the Berlin Wall, and three students at an American high school in West Germany take an ill-advised joyride to Berlin to check out the May Day workers’ rallies. The kids explore their adolescent angst, a la The Breakfast Club, on trains, in bars, and in bed, until, upon their arrival in East Berlin, they are arrested for reasons they (and we) don’t really understand.

This is the tantalizing premise behind Secret Father, the uneven new novel by James Carroll, author of 1996’s National Book Award-winning memoir An American Requiem and 2001’s acclaimed Constantine’s Sword, a history of the Catholic Church’s relationship with the Jews. But instead of the edgy, elegant thriller that the material promises, Carroll has produced a high-minded, warmhearted, and flabby novel that, despite some clever plot twists, never achieves much dramatic momentum.

The book bogs down early on with prolonged and earnest descriptions of the hidden pain that makes each of Carroll’s band of teenagers, well, a typical teenager. The leader is Ulrich, a native-born German given to pompous proclamations like ”Disobedience is how I know I am not dead.” Ulrich’s German father died at the tail end of World War II, and his mother, Charlotte, took as her second husband an American military officer doing intelligence work. For his trip behind the Iron Curtain, Ulrich has borrowed his stepdad’s bag — and stuffed inside is a mysterious roll of microfilm.

Is microfilm ever anything but trouble?

Ulrich’s companions are his sometime girlfriend Kit, an aspiring novelist who worships William Faulkner, and Michael Montgomery, who worships Kit. Timid Michael narrates the account of the teens’ adventures; the rest of the story is told by Michael’s widower father, Paul, an American banker in Frankfurt. Paul teams up with Charlotte, an icy Teutonic goddess who seems to know more than she wants to say, and the two head to Berlin — where their every move, including a few intimate ones, is closely watched — to rescue the kids.

Many thrillers collapse at the end, and Secret Father is no exception. Its climax, while ingenious in theory, is convoluted and flat on the page. What actually happened behind the scenes — some great, nasty stuff with Nazis and vendettas — is explained decades later, in the final few pages. Too little, too late; all the bad guys are long dead, and we never even knew them. The book cries out for a living, breathing, diabolical villain, or at least one complicated, corrupt, and deeply flawed figure. Every major character — and some fishy peripheral ones — turns out, once their secrets are revealed, to be nice. Life isn’t quite like that, and memorable thrillers certainly aren’t.