Young Tom Messenger has been taking care of Bonfire, the second son of the famous Black Stallion, since Bonfire’s birth. Tom has earned the trust of Jimmy Creech, the veteran driver who owns Bonfire, and Tom is eager to work with the young colt, building his strength and endurance.
But suddenly Jimmy’s health takes a bad turn, and Tom must pick up Bonfire’s reins himself. The horse is a natural, but Tom doesn’t know the first thing about harness racing. And he’d better learn fast …