On a sultry summer day in April, the kind that saps all your energy, I walk down a flight of spiral staircase that takes me 22 metres below Bengaluru’s MG Road to the spot where the Bengaluru Metro Rail Corporation (BMRCL), through Larsen & Toubro (L&T), is carrying out its tunnel construction for the underground section of a line, set to run between Gottigere and Nagawara, at full steam. Amidst the cacophony of machines and enveloped in heat and grime is 25-year-old Pallabi Modak, busy at work. Perched atop a four-metre-tall gantry crane, Modak can be spotted noting down the survey coordinates from the navigation instruments fixed on the tunnel’s ceiling.