On Manhattan’s west side, a tunnel said to be the largest public works construction project in the history of the western hemisphere nears completion: New York City’s Water Tunnel #3. After 38 years, the sandhogs prepare for the final blasts in this tunnel. With vital tunnel infrastructure dangerously close to the blast site, Master Blaster Eddie Greenan is brought in to supervise. But unexpected collateral damage from the first blast creates problems. Meanwhile, a few blocks away at the #7 Subway expansion site, Martin and Ryan reach a milestone as they finish the shaft and begin mining forward. But there’s problems with the blasting plan, and the gang reaches out for help. Back at water tunnel #3, Eddie and the hogs wrestle to complete the final blast, which would conclude the Sandhogs biggest project ever.