And By the Sword You Die

Reach the Pembroke Hospital: "Right away" is more of a guideline that a rule, since you'll probably have some XP that you want to spend. As you make your way back to the West End through Temple Garden, you may well encounter a powerful Ekon which can be a nasty surprise. The level of the Priwen guards is now as high as 32 which makes Brawlers and Chaplains proper pains to deal with. You may want to stop off at Lady Ashbury's mansion on the way since she will have some new dialogue for you. Go to the Finsbury Gate Hideout since that is the easiest way to get to the hospital. You may want to take the opportunity to rest. For reference, I had >4200XP and took two points in Cartridge Bag, bringing me to level 28.

Prepare for Boss Battle: When you reach the hospital, head up to Dr. Swansea's office to find him gone. Follow the blood trail to an elevator on the top floor. Equip yourself for a boss battle. You'll want your Pump-Action Shotgun, enhanced for chemical damage, and your pistol of choice.

Defeat Geoffrey McCullum: When you're ready to proceed, take the elevator down to face off against Geoffrey McCullum. The greatest danger in this battle is the ultraviolet light which burns you. McCullum himself fires his crossbow several times in succession and charges you with his sabre. Evade his attacks (and dodge out of the way if you find yourself burning up in the limelight) and empty your shotgun into him. When you run out of shells, switch to your pistol and finish him off. You will unlock the Bury the hatchet trophy when he falls.

Make a Choice: You will have to make a couple of choices. The first is of no consequence but the second looks as though it might be momentous. However, the only reason to select "Turn" is because McCullum is a dick and you want to waste 1000XP. "Spare" is the optimum choice here.