The Danger Signal plot
A railroad executive refuses to have anything to do with his son's widow, who ran away a year earlier. However, he agrees to raise her baby, unaware that she is actually the mother of twins. She gives one of them into his care and changes her name. Twenty years later, both boys work for the railroad, in their grandfather's department. Spoiled and unemployed, he works as a district assistant superintendent, and his brother, unknowingly, works as a firefighter at the same intersection. The twins clash over the girl in the shop, and the poorer twin loses his job.