By Mark Harris
Updated October 26, 2007 04:00 AM

Some writers try to build bridges over the chasm that separates genre fiction from ”serious” lit. Michael Chabon simply denies the gap exists. He walks on air, never looking down, and dares you to contradict his assertion that comic books, noir whodunits, boys’ stories of derring-do, and Pulitzer-worthy novels share the same DNA. In his thrilling big books — The Amazing Adventures of Kavalier & Clay and this year’s The Yiddish Policemen’s Union — his magic makes you a believer. In his small ones, you may not be as convinced, but witnessing his certainty offers its own pleasures.

Gentlemen of the Road is a small one. It’s tiny but overstuffed, and like a battered piece of antique luggage covered with exotic stickers, it’s more interesting for what it reveals about its owner’s hunger to discover new places than for its actual contents. Subtitled ”A Tale of Adventure,” the snack-size epic, ornamented with drawings, combines Chabon’s keen, inventive approach to questions of Jewish identity, bravery, and displacement with his taste for degraded forms, in this case the tumescent prose that used to bedeck every panel of a Classics Illustrated comic. Set along the Silk Road in the time of the Khazar Empire, the narrative details the journey of a couple of Jewish travelers guarding a prince and encountering battle, zealotry, slaughter, and exodus. There’s a bounty hunter named Hanukkah, a horse named Hillel, and reams of dialogue on the order of ”Leave us to settle this matter in the Khazar way. Openly. By fire and steel. And soon, Amram, today, now, before the main body of the army can return from the Crimea and surround us.”

If you just cracked a smile, you’ll have fun. But if you think 200 pages of affectionate pastiche of a so-so subgenre sounds like heavy going, sit this one out. In an afterword, Chabon, engagingly transparent about his process, reveals that the original title was Jews With Swords. His account of why that fell by the wayside is at least as compelling as the novel, and a reminder that this exuberant, exciting, language-loving writer still has brilliant adventures ahead after this rest stop. B