Science Without Conscience

Use the Finsbury Gate Hideout to reach Doris Fletcher's Theatre.

Kill the Priwen guards outside and enter through the front door.

Proceed past the lobby into the theatre proper.

Eliminate the Priwen inside, including a Chaplain and a Brawler.

Search the table to find McCullum's Report and acquire the Theatre Stage Key.

Go through the door on the left of the stage and head downstairs.

Use your blood sense (a special vision mode) to locate Dr. Swansea behind a locked door.

Go through the opposite doorway and defeat the Priwen Exterminator.

Enter the unlocked door and search the shelf for the lore item, The Vampire Knight (29/30).

Search the table to find William Marshal's Memoirs and acquire the Theatre Basement key.

Examine the notice board above the table for a Pinned Note, which indicates the safe stores sensitive evidence.

Return upstairs to the stage and go through the opposite door.

Head upstairs and defeat the Priwen guards, including a Chaplain and a Brawler.

The Brawler is Rodney, mentioned in the Pinned Note, and drops a Brand New Key.

Return to the office in the basement and unlock the safe with the Brand New Key to retrieve the Personal Notebook. Warning: DO NOT READ THIS notebook, as it will cause you to fail the investigation and lock you out of two trophies.

Unlock the door leading to Dr. Swansea's room for a cutscene (an in-game cinematic).

During the conversation, you will learn how the Skal epidemic started.

At the end of the conversation, you will have a choice to make.

If Pembroke Hospital's health status is not in the high 90s, consider selecting "Turn" to potentially prevent the district from becoming Hostile due to Swansea's death and random illnesses.

Choosing to "Embrace" provides a massive XP boost.

Choosing to "Turn" has a significant cost but grants Edgar's final hint and later dialogue.

If your choice results in his death, you will gain his cross and a Small Key.

Regardless of your choice, you will unlock the Dying Swansea trophy.

Before leaving the room, search the desk for an Old Love Letter, which can be read to unlock the final hint for Calhoun Russel.