The story unfolds with Steve and his faithful bulldog, Mike, on land after a severe disagreement with the captain of the Sea Girl, leading to Steve being ousted from the ship. Seeking entertainment, Steve stumbles upon Flash Larney’s Gigantic Circus and Animal Show, where he is drawn to a challenge—fighting in the ring for prize money against the purported West Coast champion, Battling Bingo. Steve’s victory lands him a job as the circus's new star attraction, tasked with taking on all comers for a cash prize.

As the circus travels, Steve becomes a crowd favorite, known for his unbeatable prowess in the ring, which he attributes to his rugged life at sea and his extraordinary condition. His tenure with the circus is marked by a series of fights against a wide array of challengers, culminating in a match against a surprise opponent in the mining town of Ironville. This opponent turns out to be none other than Bill Cairn, the Ironville Blacksmith, a figure revealed to be a formidable heavyweight boxer rather than a local craftsman. The match is a brutal affair, with Steve enduring a tremendous beating but persistently rising to continue the fight, driven by his indomitable will and the deceit played upon him.

The tale reaches its climax amidst a chaotic circus fire, with animals escaping and panic spreading. Steve, in the midst of defending himself and the audience from the dangerous animals, is reunited with his former captain, who seeks his help to deal with a new threat aboard the Sea Girl. Despite their past conflict, the captain’s appeal to Steve's loyalty and pride as a sailor convinces him to return to the sea, leaving behind the circus life for the familiar challenges of the maritime world.