Tapestries of Spying

These tapestries, usually very elaborate with people gallivanting about hunting, or singing, or making war, were once what every Leader wanted in the castles of their rivals.  There was a link between one of the figures on the tapestries and a stone the user would have in their possession.  The figure usually had a smaller, matching gem sewn somewhere into the cloth.  The user of the stone could activate the magic once every day for an hour, or sacrifice a few days for additional hours.  For every day it has to recharge another hour of spying may be used.  The user can see and hear everything the figure in the tapestry can see and  hear and nothing else.  The figure can not move, but does have 180 degree view from its position on the tapestry.  After the user is finished he can do nothing strenuous for an equal amount of time he spied because of the draining effects of the magic.  (In game terms there is a huge minus to attack, dodge, spell casting, etc.)  There are few of these tapestries still in exsistance, and ones with the matching user stone is even rarer.