What should the box contain?

I'm writing a story about a thief named James. I takes place before gunpowder, but i'm not sure what time period...maybe medieval time? I'll figure that out later. Anyway, I got to the part where James has stolen this box from the village (it's home to a wealthy, powerful and greedy lord), and he runs to his hideout in the woods under what everyone calls the Beginning tree, even thought they don't know why. James thinks he as stolen a valuable item like rare jewels, important documents he could sell to the enemy, a solid gold crown...you get the idea... because the guards chased and yelled threats longer than usual. James usually enjoys running away because he never gets bored due to the fact that it doesn't last long. When he opens it he finds a .... thats where i'm stuck. I want it to be something so simple that anyone could have something like it. Not a stick or a nose...an item you can buy, but for really cheep. He will later discover it is a magical item, and he finds out what the lord of the village is up to (to be determined later). what should the item in the box be? also, what do you think of the story idea (it's still a rough draft)