QUANTICO - "Clear" - This week the NATS learn how to source information from confidential informants, but when they test their skills in the real world, they soon realize being an agent is not as easy as it seems.  Meanwhile, in the future, Alex and a fellow agent find themselves in a life or death situation when they are forced to provide classified information that could result in deadly consequences on   "Quantico" SUNDAY, MARCH 13 (10:00-11:00 EDT) on the Walt Disney Television via Getty Images Television Network. (Photo by Walt Disney Television via Getty Images/Phillippe Bosse/Walt Disney Television via Getty Images)