Rusty Key

The Rusty Key is a quest item in Pathologic 2. It is required to unlock the Haruspex's Lair.

Pathologic 2
If the Haruspex enters Isidor Burakh's House on Day 2, he will find the Rusty Key in a box in the second floor backroom of the house. If he fails to enter Isidor Burakh's house during Day 2, and approaches the house in the early morning (pre-dawn) of Day 3, he will be greeted at the door by the Bachelor, who will give the Haruspex the Rusty Key. If neither of these things occur, the Haruspex will instead receive the Rusty Key from a messenger at dawn on Day 3.

After finding the Rusty Key, the Haruspex will receive updates to the mind-map suggesting that he either speak with Big Vlad or Vlad the Younger about it. It is unknown which Vlad he should speak to, as the note is simply signed with V.O. After talking to either Vlad, he will discover that the Rusty Key is actually from Vlad Jr.

Alpha Release
The Rusty Key was an item in the Alpha release of Pathologic 2. It was obtained from a box in Isidor Burakh's House for a quest on Day 2 of the Haruspex's route.

It was used to open the door into an abandoned room in the Factory, leading to the Haruspex's Lair. It has since been replaced with a note and key in the full release of the game.

The Alpha version of the Rusty Key is accessible only through Console Commands.