. >> thierry stern is dressed like he's going into an operating room.that's because the work here is like surgery. it's so precise, they have air filters to prevent even a single speck of dust from getting inside a watch. and watchmakers in this room can spend years making just one timepiece. but we're here to see patek's masterpiece being built. price tag -- $2.6 million. it took 100,000 hours to develop. over 1,300 parts, each of the tiny pieces are handmade and measured in micrometers. assembling them isn't a job. it's a science that required six new patents. with 20 complications, it's the most complicated wristwatch patek has ever built. they don't even call it a watch. this is a wrist-format timekeeping instrument. its best feature is a face that flips. and super rich watch collectors know this sound... [ watch chiming ] ...the signature patek chimes. >> as we call it now, grandmaster chime. >> but even if you can blow $2.6 million on a watch, that doesn't mean you can own it. you actually have to apply for it and prove that you're a sophisticated