In his early days as a gunslinger, in the guilt-ridden year following his mother's death, Roland is sent by his father to a ranch to investigate a recent slaughter. Here Roland discovers a bloody churn of bootprints, clawed animal tracks and terrible carnage--evidence that the 'skin-man',
a shape-shifter, is at work. There is only one surviving witness: a brave but terrified boy called Bill Streeter.
Here is a link to SK.com with info on The Wind Through the Keyhole. I haven't looked forward to a book this much since Dark Tower 6. It takes place in between Wizard and Glass and the Wolves of the Calla. Looks like there is a flashback to Roland's youth and within that story, there is another flashback. Coming April 24, 2012.