Cyber experts start getting called into electric, water, pipeline, railway, and transportation hubs around the country. Hackers have found a clever way to embed in these systems, using a small, unsuspecting device in everyday Americans’ homes. And once these hackers get in, they’re not dropping the usual malware, or sucking much of any data out. Unlike their predecessors, these hackers are very careful to cover their tracks. It appears they’re just lying in wait. Sleeper cells waiting for marching orders. So what’s the trigger? And what happens if they pull it?