 Boots Murphy tries to convince his friend Arthur Duffy to bet on a particular horse. Turns out Boots has developed a secret formula that will turn any nag into a stallion. Arthur is a boxing manager and knows nothing about horses but he convinces Boots to inject a has-been fighter, Soldier Fresno. The drug apparently works wonders and Soldier wins a big fight so his manager sets him up for fight after fight. When Soldier finally gets a shot at the title, Arthur decides to up the dosage with unexpected results.