The Operative is one of four Documents in Cold Darkness Awakened (additional content for Rise of the Tomb Raider). It belongs to the Contingency Plans set, containing messages addressed to Konstantin from an unnamed Trinity agent.
I've accompanied the men from Echo Team to the research site. As per your instructions, not even the Sergeant in command is aware of our secondary objective. He believes I am just a translator, and we are here to aid in the recovery of the Divine Source.But I've already confirmed what you and I suspected: This was indeed the research base mentioned in the redacted documents. They were close to a breakthrough in unlocking rapid human improvement, but not close enough. The test subjects overwhelmed and killed the staff. We will be cautious, but I will see what research I can recover.