On the 7 Subway line extension project, Walking Boss Martin Hostetter and Foreman Ryan McGinty ready their gang for an important two weeks. They are preparing the final few blasts to complete the giant subterranean cavern. Over the past four months this relatively inexperienced crew of sandhogs has refined their skills and come together as an effective gang of drill and blasters. But as they work, mechanical problems slow their progress, and frustration mounts. Over at the East Side Access site, the West Tunnel mole gang confronts one obstacle after another in their efforts to mine 25 feet a day. Broken components on the mole shut down production and the gang must go out in front of it to get it fixed. When the 300-ton mole derails, the gang is thoroughly tested, using hand-tools and ingenuity to get it back on track so mining can continue.