Infusions are phials (or bottles) of potent formula which allow Booker to increase the potency of his Health, Salts, or Shield to a maximum of ten (per phial claimed). Note that the five bonus phials of infusion in the Early Bird Special Pack (see: DLC) are not included in this total.
Comstock Center Rooftops
Note – the magnetic repulsion formula is not a phial — or even an item that can be missed.
INFUSION 000 The official Brady Games guide marks this area as having three Infusions, but only shows the locations of the two below. This means that technically, the shield is the “first” Infusion, bringing the number to 25.
At the Fraternal Order of the Raven’s main chapel, look for a phial of infusion on the main altar, right next to the key to the Lansdowne Residence chest.
Locate the key at the Fraternal Order of the Raven’s main chapel (under the Infusion bottle). Take the key back to the Lansdowne Residence (backtrack) and open the locked chest for this Infusion bottle.
Monument Island Gateway
On the skyrail tutorial, make a stop at the first blue-lit platform (labelled “Monument Tower Maintenance”) on the lowest part of the skyrail. Check inside for this phial of infusion on the roll-top desk.
Behind the desk where the voxophone is on in the room with the large speakers (past the photography and projector rooms).
The ticket master’s office can be accessed from the back; check the door in the hallway before stepping outside towards the Tesla coil and the gondola. There is a phial of infusion in the ticketing office.
Behind the locked door (locked by 1 lockpick). After you locate some lockpicks for Elizabeth to use, she can open the locked door in the Welcome Hall for this phial. Check the whole office and you will see it easily.
Hall of Heroes (Going There)
Find the Code Book for the Hall of Heroes and open the secret room in The Fellow Traveler. The phial is on the side of the secret room.
Inside the Hall of Heroes
In the Comstock Statue room where Booker is ambushed by some enemies, enter the workshop where the enemies came from to find this phial stored in the back. A destroyed Cornelius Slate statue will be in this workshop.
Hall of Heroes (Courtyard)
When fighting Slate’s men in the Courtyard, face the message on the wall that reads “We deserve to die as soldiers” — and turn 90° left. Go through the door and into the workshop and locate the phial in the toolbox near the voxophone (not shown above). You may want to do this after you deal with the motorized patriot.
Return from the Hall of Heroes
On a desk about the First Lady Zeppelin, before you take off with Elizabeth for “Paris.”
Near to the gibbet is a door leading to the lower holding cells. Go inside to the lower holding cells and investigate the cells for the phial.
Worker Induction Center
The locked upper office of the train station (5 lockpicks) has a phial on one of the desks. You may need to have Elizabeth open the basement first so you can find some more lockpicks first.
Good Time Club
On the bottom floor of the night club, there is a private bar past some closed doors near a Dollar Bill vending machine. The phial is inside, next to a “Free Sample” sign.
Plaza of Zeal (Return)
The Code Book from the Good Time Club lets you solve the puzzle room in the Plaza of Zeal. Change the time on the wall clock and pick up this phial in the hidden safe.
On the street in Shanty Town, there are two ruffians who are robbing some homeless people. Kill both and check the crate behind them for a phial.
Bull House Impound
In the Impound Building’s second floor, the room just past the Medical Kits tear has a phial in the locked chest by the voxophone. The key to the locked chest is in the Graveyard Shift cellar (same room with the guitar).
Next to the Medical Kit tear on the Impound’s second floor, there is an evidence room that’s locked (5 lockpicks). Have Elizabeth crack the lock for this phial.
Complete the story sequence with Elizabeth and Daisy Fitzroy to gain access to the locked rooms. This phial is in the room with the table.
After Elizabeth cracks the hairpin lock in Prosperity Plaza, there is a locked gate (requiring 3 lockpicks) with a phial of infusion in the area it blocks off. Check the washtub after you have Elizabeth open the optional locked door.
Button under the cash register opens secret room with this phial of infusion; requires the voxophone from Founder’s Bookstore’s basement reading room or the button will not activate.
Wilson Bros. & Company Bottling Works (red awning store past Hudson’s clothing boutique) has a phial of infusion in the window. You simply need 3 lockpicks to break inside the store.
Bank of the Prophet
Requires the Code Book (Downtown Emporia) from Hudson’s in Downtown Emporia. In the vault, there is bloody graffitti of “HOARDER”. Use the code book to open the secret room for a phial.
Memorial Gardens (Emporia)
Inside the Lutece Lab, second floor bedroom. With its characteristic flicker, the phial is hard to miss.
Rescue Elizabeth and secure three lockpicks. There is a locked door (requiring 3 lockpicks) between the two sets of stairs that led to the power switches on her torture machine. Open the door to the doctor’s office and claim the phial.