Rowan's Impossible Case

You ignore the body for now and scan the study.
A chair overturned. A glass shattered. Books knocked loose from one shelf.
The fireplace tools hang neatly on the wall.
Except one.
The poker is missing.
Ash near the hearth has been disturbed—something was wiped clean here.
You also notice the bookshelf itself is slightly crooked.
A hidden panel.