Press the green flag.
https://www.google.com/search?q=secret+underground+lab&safe=strict&rlz=1CASQGI_enUS814&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjey5Kon4zhAhVGSK0KHf0nCBMQ_AUIDigB&biw=1366&bih=697#imgrc=Lm5uE1oLxPnfjM: https://www.google.com/search?q=secret+underground+lab&safe=strict&rlz=1CASQGI_enUS814&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjey5Kon4zhAhVGSK0KHf0nCBMQ_AUIDigB&biw=1366&bih=697#imgrc=HKsvCzdFb95qOM:
