Tracy's plan was to get everyone suited in labcoats and dust masks with filters so they look like a biohazard team, then fast talk the guards into thinking there had been a leak of some odorless chemical, and having each person incapacitate one if the guards when they got close. That way there's no giant explosions, car crashes, or really outlandish things that make them stick out like a sore thumb and everything is quiet and easy.