This is similar to the previous Butcher's Bill quest except instead of finding the status of a place, you're tasked with learning the status of a person, Agent Blackbird. Again, speak to Doctor Carrington for the assignment. Note, if you plan to do this immediately after Butcher's Bill 1, you might have to leave then reenter Railroad HQ to trigger the conversation.
Your first destination is another dead drop at a random location. Our pick up was near the Revere Satellite Array.
The information from the dead drop will lead you to a random safehouse. Our particular journey led us to a Raider stronghold at the other side of the map. Inside, we found what was left of Agent Blackbird. Pick up Blackbird's belongings and return to Carrington to make a report and close the quest.