A construction crew led by engineer Duncan Clooney needs to move a wagon load of nitroglycerin through Laramie as they take it to Cheyenne. A demonstration of the power of the explosive makes Troop a believer that Laramie must be evacuated. Eggers, who works for Clooney, has had enough and convinces his co-worker Falk they can be rich using the explosive to rob the Laramie bank. They tie-up Clooney and in Laramie take Johnny hostage. Troop returns as they enter the bank resulting in a stalemate. Johnny convinces Falk he should release him as Falk doesn't want to kill anyone. Eggers blows the safe and tries to escape the bank with the leftover explosive after Johnny removes the wagon load out of gun range.