God's Coffin is the sequel to Wade Garrison's Promise, and takes place five years after Wade rode out of Harper, Colorado leaving Sarah, the girl that loved him behind.
Now, six years later, his old friend, Sheriff Seth Bowlen, in Sisters, Colorado is in trouble and needs help. Sheriff Bowlen sends a wire to United States Marshal Billy French in Santa Fe, New Mexico who in turn sends Deputy Marshal Wade Garrison to help their old friend.
Innocently, Wade decides to take his wife, Sarah, and son, Emmett, with him so they can visit her family in Harper, a small town northeast of Sisters.
As Wade and his family board the train in Santa Fe, he could not have known that a terrible storm of violence was already brewing, and this fateful decision could destroy his wife and child.