The former Soviet Republic of Georgia, which is located in the heart of the Caucasus Mountains and has a complicated past, is a mostly forgotten pocket of the world. But for four American adventurers, it’s ripe for exploration. They plot out an ambitious plan to transect the rugged Caucasus, a raw landscape filled with rocky passes and sketchy border regions, before ending their journey in the beautiful Kazbegi region. On mountain bikes. And unsupported.

What they encounter are colorful locals, ancient trading paths, snowfields, stone-faced border patrolmen, a fair amount of suffering, wild storms and a host of unknowns. All the ingredients, in other words, of a great adventure.