Caleb Wilson, owner of a freighting line, accepts a contract from Ben Jarrett, manager of the Deep Tunnel Mine, to deliver tons of ore to the smelter by a specified time. In order to obtain the contract, Wilson had been obliged to put up a $20,000 cash performance bond, but Wilson doesn't know this is just a scheme by Jarrett to get the money. When accidents happen to his wagons, it looks as though he will have to forget the money. But Cisco and Pancho, rescuing one of his wagons from an attack, get busy. Wilson is certain that Carson, the smelter owner, is behind the sabotage. Cisco and Pancho, however, finally prove Jarrett is to blame.