The Falcon in the Barn (Book 4 Forest at the Edge series)
by Trish Mercer
The problem with everyone, Perrin concluded, was that they couldn't see what he did. Shem said his mind was confusing him. Mahrree said it was nightmares. His children said nothing. But he knew he was surrounded by Guarders, masquerading as cats. But an army is also assembling--in the forests and wearing green and brown--because they have their own plans for the wounded falcon in the barn.