Callum stared into the distance through tired, half-closed eyes. He hadn't slept properly for weeks and as their cart trundled tediously on its way he would find his head sagging forward and his eyes threatening to close. But each time they did so, a bump or a jolt would snap him awake and so the cycle would continue. The cold certainly didn't help matters either.

Why was it so cold in the middle of summer?

He raised his head and stared long and hard at the dark blotch ...