How to fix water damaged drawing on Photoshop?

[ArtTeacher660]

A friend asked me to fix a drawing that got damaged in a flood. I am having a difficult time with this one. Any suggestions on how to restore this sentimental drawing?

[kevin stohlmeyer]

You could use adjustment layers to bring contrast to the line drawing and lessen the paper gray. 

After that, its traditional retouching - stamp, healing tools, dodge and burn to even out the paper color.