Stories that have a sneaking puzzle put you into a situation where you must avoid being seen or caught by guards, while trying to make your way to an exit zone.

The exit zones are the blue colored squares. You're the small green circle, and the guards are the large red circles. Tap or drag to move, but the guards will also be moving. If you ever fall into any of the guards' fields of view, they've seen you! What happens then depends on the story. That generally isn't the end of the story, but you'll definitely be taking a different path than if you'd made it through without being seen.