Percy nods, apparently catching the signal, and sits down next to Cassandra to coax her into helping him look through the pack. More bread, an irregular hunk of cheese, half of a long sausage that will probably look and smell to Crichton rather like hard salami; a small tin pot, badly dented but not cracked, with a little cloth pouch in it that proves to contain tea. "Oh, gods bless that man," Percy says fervently at that last, and immediately takes the pot the few yards down to the river to fill it with water.

He's back in time to see Crichton light the fire, and his eyes go very round behind his cracked spectacles. "That thing isn't magic, is it? How does it work?"