We continue Dolores Chapter 2 in after acquiring the baby monitor.
Now pick up the hammer when you leave the room. Go back. Walk through the mirror you came from. You ae now back in the main house. Walk through the corridor and climb the stairs. Before the bathroom on the 1st floor go to your left. Walk to the end of this corridor and break the mirror in front of you. Go through the mirror. Walk straight forward and you see a floor with some holes in it. You walk fast over the floor because Dolores is right behind you.
No break the floor. Jump into the floor hole you just created. If you look above you see Dolores. Walk straight forward and up the stairs. You enter a bright lit area. Walk towards the light and you see a mechanical crank.
You found the mechanical crank. Start looking for the bloody knife.