At the Croton Filtration Plant in Bronx, NY, Walking Boss Morgan Curran and his gang work to complete the new tunnel's connection to the 118-year old New Croton Aqueduct. As the concrete pour begins, signaling the winding down of this job, Morgan begins his search for the next big drill and blast job. Morgan is reminded of why he hates concrete so much when clogs in the lines slow progress and injuries strike the crew. On the east side of town, the sandhogs are working on the first major upgrade to the LIRR in over a century. And new tunneling technology is moving in that could make drill and blasting obsolete - signaling the end of an era for NY's hard rock miners. Back at Croton, the completion of the lower tunnel forces Morgan to face the worst part of being a boss laying off some of his gang.