Moon Shadow — Dawn Stewardson

The year is 1887

Schoolmarm Emma McCully is scared to death. Her brother's hightailed it to Tombstone, Arizona, the roughest town in the West. And he's about to be hanged for horse thieving!

Thank heavens Will Lockhart, her brother's childhood friend, showed up on her doorstep, volunteering to help.

But Will is big trouble, too. He's set her heart aflutter. Worse, he's plumb loco. He calls himself an astrophysicist." He totes around a gizmo called a "pocket computer" And, he claims that when he moved away as a child, he traveled more than a hundred years into the future, where he's been living ever since.