1860: Robbie Grant injures his leg placing explosive fuses in an embankment while working as a Navvy with his father Giant while local farmers oppose the new railway. Engineer John Fowler has high expectations of manager Henry Bridgman and low expectations of the navvies on payday. Robbie has to prove himself in the sight of the other navvies, as he gets to know their landlady Martha's niece Deborah.
Engineer of the line Mr Fowler offers Robbie a job, and Deborah teaches him to read and write. Giant plans to seek Martha's hand in marriage. Tragedy strikes and Robbie wants to leave instead of taking his job at Hampton Loade.