Haley burns the piano

At then end of the episode Haley is sat at her piano and flicks a candle down on to the keys and it promptly starts to burn and she just sits there while it is burning.
Luckily Nathan finds her and gets her out but it breaks your heart because even as Nathan is pulling her away from the burning piano her eyes are glassed over and you know she isn't really in that room with him in her mind and has no real idea what she is doing.
Nathan asks her what happened and all she says is i need to go and call my mum.
As a viewer you know at this point that things are not good for her. This isn't the first time you see cracks in this episode but it is the first time you see just how low she is.