The Lost Letter on the Butterfield Trail

It's a new school year and Ed and Jimmy have made friends with sisters Maggie and Grace. While off on an adventure along the Brazos River, the four friends discover a broken-down, abandoned stagecoach partially submerged in the river. Inside the coach is a sealed jug containing a lost letter. Can the friends solve the mystery of the lost letter? Join Ed, Jimmy, Maggie, and Grace as they set off for a new adventure on the Butterfield Trail.