William ran a hand through his hair tiredly, this time remember to transfer the puffskein first. "And whatever it is hasn't affected the jarvey?" It had seemed like a good lead, but they were all jumping at straws trying to find a cure.
He dropped his head back and closed his eyes, thinking. "There's a Muggle story," he mused. "About canaries and coalmines. They would take a bird with them into dangerous areas, and when the bird died, they knew it wasn't safe for them to be there."