Magnus is a huge, hardworking horse who loves his job at the Broadway Firehouse. Whenever the fire alarm rings, he and his horse partners, Billy and Sparks, immediately spring into action. The firemen rely on them to pull the heavy steam pumper to put out dangerous fires, and Magnus is incredibly proud of his important work. But everything changes the day the captain arrives with a loud, motorized fire engine that does not need horses at all. Suddenly, Magnus and his friends are out of a job and facing retirement in a quiet pasture. Unwilling to give up his duties, this high-spirited horse sets out to prove that loyalty, heart, and a little bit of horse sense can still save the day!