The Firefly Map is a note on a dead Firefly in the subway station downtown, on the stairs between the two escalators. It is the body to the right of the one carrying a Molotov cocktail.
The note sends the team to meet a second Firefly group at the Capitol, the gold-domed building, and describes the girl they are protecting: 14 years old, red hair, around five foot three.
The girl is Ellie. Joel and Tess conclude from it that these dead Fireflies came out of the quarantine zone and are not the group they are meeting.
Note to Derek
The Note to Derek is a scrap in a drawer behind the register of the first shop on the left in the subway room full of clickers. It holds the combination for a safe close by.
Davidson's Firefly Pendant
Davidson's Firefly pendant lies underwater in a stone rotunda in The Capitol Building section of The Outskirts. It belonged to Melinda Davidson and is easy to swim past.
Evacuation Leaflet
The Evacuation Leaflet is an old FEDRA warning on the right-hand pavement in downtown Boston. Once you climb the collapsed street and Tess and Ellie start talking about the bombing, look by the base of a traffic light a car has hit.
Field Ops Log
The Field Ops Log is a soldier's patrol record inside the Goldstone Building, the tilted skyscraper downtown. Climb the stairwell toward the fifth floor; it lies beside the second dead soldier, along with a couple of 9mm rounds.