Spot the Anomaly

The new kid at school shows Miles a game on his phone. Walk the hallway. Spot what's different. Turn back if you see it. Except the hallway in the game is their school hallway. And the anomalies start showing up in real life — a door handle on the wrong side, a clock running backward, a poster with text that wasn't there yesterday. Miss one and walk through, and something follows you home. Dex thinks it's the best game ever. Miles thinks the game is playing them. The new kid hasn't been at school since he handed over his phone.