After many years working together, Mike and his coal-powered steam shovel Mary Anne (whose name is a reference to the Marion Power Shovel Company) face competition from more modern gasoline, electric, and diesel shovels. Searching for work, they find a small town about to build a new town hall. Mike offers that if he and Mary Anne can't do the job in a single day, the town won't have to pay them. The town's selectmen – who believe the work would take a hundred men a week – hire Mike and Mary Anne, expecting to get their new cellar at no cost. Privately, even Mike has some doubts. At sunup the next day Mike and Mary Anne begin work. They are successfully able to complete the cellar, but Mike realizes that he neglected to build a ramp to get Mary Anne out. A child suggests that she be converted into a boiler for the new building's heating system, and that Mike become its janitor. Mike and Mary Anne settle contentedly into their new jobs.