From "Blue Bells of Scotland" by Laura Vosika

Where could they all be? The MacDougalls couldn't have returned so quickly for vengeance. They couldn't have emptied everyone out so swiftly and silently that he slept through it.

Niall stooped to slide the dirk from his boot. Its smooth metal blade ran cold up his leg. A bead of sweat inched down his jaw. He scanned the desolate castle, right and left, and straightened, pushing the long, dark hair from his forehead. The walls: they were like his castle walls, but—he studied them—not quite.

A wave of dizziness crashed over him. He squeezed his eyes shut, braced his hands on his knees for a moment, and pushed himself back up, staring at the ruins where the stables, blacksmith, and armory should have been. The close was no longer beaten earth, grazed by sheep, but soft with dewy grass, like an English garden.

He touched his temple, under his hair. The lacerations were still rough, tender to the touch. The wound ached as if it were only days old. Had it caused him to sleep long enough for people and sheep to disappear, for grass to grow?

...and walls to crumble?