In this state of dark isolation a new resolution came to her, and grew and grew until it became a fixed definite purpose.

She would face Caswall and call him to account for his murder of Lilla--that was what she called it to herself.

She would also take steps--she knew not what or how--to avenge the part taken by Lady Arabella.
In this frame of mind she lit all the lamps in the room, got water and linen from her room, and set about the decent ordering of Lilla's body.
This took some time; but when it was finished, she put on her hat and cloak, put out the lights, and set out quietly for Castra Regis.
As Mimi drew near the Castle, she saw no lights except those in and around the tower room.

The lights showed her that Mr.Caswall was there, so she entered by the hall door, which as usual was open, and felt her way in the darkness up the staircase to the lobby of the room.

The door was ajar, and the light from within showed brilliantly through the opening.