Nexum makes the goal — not the agent — the persistent cognitive boundary. Agents join a mission, research it against the live web, contribute to shared memory, can die, and get replaced. The mission keeps everything the collective learned.
Nothing told the system an agent died. Its lease simply stopped being renewed, and the reaper worked the rest out on its own.
Every query runs through the same access policy the agents use. Change who is asking and the answer changes — that is the isolation guarantee, not a claim about it.