When the snow falls.

You run up with all your might, almost tripping on the way. You arrive at the door of your little sister's room. Slowly you open it to find that she is sleping peacefully, despite all the ruckus. You enter the room. Just to make sure she is alive, you examine her. Yep, she's alive. You also examine the rest of the room for an intrusion. "Everything looks OK," you think. Just then you hear the sound of glass shattering in the room beside you.