David Thornton, a high school senior who is about to graduate and head to college, is a Civil War enthusiast. He loves studying history, and he loves Civil War memorabilia. His great-aunt Gin knows this, of course. She has a special gift for his graduation. It is a letter written by Abraham Lincoln. Meanwhile, she has David go digging through her attic for other Civil War letters.

In the course of searching the attic, he finds a strange helmet. Gin gives him the possibly priceless head piece.

It doesn't take a thief long to hear of the Lincoln Letter, and it is gone before David even sees it. It is a treasure with a possible answer to a great Civil War mystery.

On a quest to find the Lincoln Letter, David and his friends are soon pursued by the "collector".