back in time adventure

Computer generated image of a market scene

You move into the space between a nearby cabinet and the wall, hoping no one will see you for a few minutes and then you will quietly sneak up to join your class. Standing in the dark you notice a small, faded painting on the wood of the cabinet back. As you look it becomes brighter. It seems to be a scene of a marketplace. You realize you are still holding the thread. You start to hear the sounds of people talking.

Are the sounds coming from your class? If you think so, drop the thread.

Are the sounds coming from the painting? If you think so, keep holding the thread.