Fenris only offers a blank, slow blinking look for the demonstration, and then suddenly gives a light huff of amusement, one corner of his lips twitching upwards.

"And to think I've been needlessly suffering through headaches my entire life," he intones dryly.

But his expression turns rather quizzical. "Short of a direct blow, I can't think of many other things that could render someone unconscious for so long. A poison or sleeping powder, perhaps, but nothing that acts so quickly. Besides which, most slavers usually have a mage or two with them to help keep people under control quickly for that very reason."