Find Erin's cell - description | Chapter 5: The Forsaken Thief Guide
Last update: 11 May 2016
Start by exploring, thoroughly, the entire main area in the old prison [Old Prison - Reformation]. On the desk, there is a book (Report: Aggression), and there are Syringes - 10+6G in the drawers. Also, you can try to access the crate in the North-Eastern corner of this room (an easy climbing required) and collect the Fire Arrow, which may come in handy soon.
Unfortunately, all of the remaining areas, in the old prison (they have been described further in the text), are occupied by monsters and, as much as monsters of this type have been avoiding you, so far, you need to take into consideration the fact that they will attack you on sight. Therefore, you need to avoid being spotted, at all costs because the creatures are very agile and they deal a lot of damage in melee, and can kill you in 1-2 blows. While exploring the prison, use to your advantage the fact that the monsters are using their sense of hearing only. Therefore, you do not need to avoid well-lit areas, but try not to move too fast. I recommend that you implement the same tactic as in the case of dog cages and bird cages so, apart from crouching press the sneak key/button. IF you, out of a sudden, walk into a dangerous situation, you can try stopping and waiting for the nearby monsters to walk away (most of them remain in constant movement).
If you want to, you may start eliminating the monsters staying in the area, and what you can use to your aid are the two kinds of arrows. The Fire Arrow can be used to set on fire places where oil was spilled. The easiest way to locate those slicks is to use focus. The second useful type of arrow is Blast Arrows. In this case, you can aim it directly at the hostile creature. A successful hit and an explosion should kill the opponent.
The less aggressive method is to use the nearby lamps and the fact that the monsters are highly vulnerable to light. you can wait for the specific creature walks under a lamp and turn on the lights, which will bring the opponent's health down and (which is even more important) drives the monster away, temporarily. Lamps are also a perfect means of hiding from monsters, after Garrett is spotted but remember that, most of them, after being turned on (the switches on the walls), remain active only for a dozen-or-so seconds.
There are two different paths that lead into the Western part of the prison. I recommend against taking the Northern corridor, because you are sure to bump there into the first monster which is difficult to walk around. It is much better an idea to reach the central balcony neighboring the main area and jump down to the lower level to land somewhere near the stairs between both levels. Regardless of the path that you have taken, keep moving ahead systematically and watch out for the elements of the environment (i.e. broken glass and vases, which can alarm the opponents to your presence). Note - these objects can also be used for the elimination of the enemy creatures, because you can, this way, lure them into specific areas and attack them with arrows or turn the light on.
If you plan on leaving the prison as soon as possible, without risking the loss of health, skip to the very bottom of this page. Otherwise, it would be good to start exploring the area, while trying to keep precautions. I recommend that you try to reach the rooftop of the central bridge, on the prison's upper level. This becomes possible after you use a Rope Arrow in the area shown in the above screenshot, which will allow you to obtain the Mechanical Eye (Unique Loot - Mechanical Eye), which is impossible to obtain in any other way.
While exploring the old prison, you can also obtain two Syringes - 10+6G; (one of them at the blocked passage to the South), a Watch Seal - 20G, Surgical Scissors - 20G, three Fire Arrows; (two of them in small crates) and an Urn - 15G. You should also remember to explore the two side corridors (the Northern and the Southern) at the lower level of the prison. There, you can find two Syringes - 10+6G, a Magnifying Glass - 10G and a ring (Memories of the Dead - Child's Memory).
The exit from the main part of the prison is in the Western part at the lower level of this location. You should not haste to reach the exit, if you have not been killing the monsters, especially that there is, at least, one of them walking back and forth between levels. Pick up the Syringe - 6G and the Poppy. Then, be on your way to the West and squeeze between the crates [Old Prison - Maximum Security]. Proceed to the West and pull the successive levers. After the attack of the monsters ends (this is a cutscene and you do not need to put up any fight) complete your journey.