Fens Street Sewer

The entrance to this location is the manhole with the skeleton.

You'll find “Dear Detective” holotapes along the way from the Fens Phantom. The first one is on the wooden cabinet near the entrance. The second holotape is found on a grill along the path.

When you reach the large hall with radioactive barrels, find the doorway leading to the next tunnel to the north. Head to the next large hall with more feral ghouls then continue forth until you reach the next setup. The third holotape is found on the table. Be careful since there's a gas leak here.

Continue to next room with the stairs and open security gate. Past that gate is an Expert safe, the fourth holotape, stealth boy, and an issue of Tumblers Today on the table nearby.

In the west side of the room beside a large machine, there's a red steamer trunk. In the hidden room past the security gate to the north, there's a flamer and a stimpak inside. Now take the stairs and follow the straightforward path until you reach the first corridor leading to the exit.