Why is there nowhere to hide? Because, according to the official CBS synopsis for the premiere, "The island of O'ahu goes on lockdown when Five-0 hunts a terrorist who starts using weaponized drones on civilians."
It's a head-scratcher imagining how locking people on an island covered by drones will be helpful, but that's why we have Hawaii Five-0 on the case!
The bigger question is this: Will McGarrett and Danno be able to put petty differences aside while they investigate?
It might be difficult since they "must go for a mandated review with a psychologist, resulting in a session which looks a lot like couples therapy," according to the synopsis.
It seems like a bad time to be dredging up their bromance issues, but if it brings levity to an otherwise tense situation, bring it on!