Turn an enemy operative into a double agent, that operative will give you a report of every message he/she either sends or receives. If you have several double agents, they'll all report the messages they send each other, one after the other. It can be unintentionally hilarious.
Agent A: "Contacted Agent B, told him we're out of milk."
Agent B: "Was contacted by Agent A, she said we're out of milk. I told her I'd go pick some up."
Agent A: "Was contacted by Agent B, he said he'd go pick up some milk."