Missing Window

  Crash!
  I wake with a start, as I hear glass break. Still groggy from sleep, I force myself to some level of consciousness. I roll out of bed, and in the dark, fumble through my nightstand drawer. Finding my revolver, I tip toe to my door, slowly open it, and peer out. The window at the end of the hall is sealed, and thankfully, solid. Moving in a crouched position, I dash down the hall, to the next bedroom. I suck in a quick breath when my foot presses down on a loose floorboard, releasing a loud squeak in consequence. The sound reverberates throughout the entire house.
  After waiting through a full minute of silence, I relax. Slightly. Then, with a gun in one hand, I push the door open. Peeking in, I look at the window, just above the bed. Unsurprisingly, it too is untouched. With a quiet sigh of relief, I pull my head from the room, and continue to the living room.
  I stop short, leaning back on the wall corner. My head turns around the corner, gun following below, but I don't see so much as a shadow. All three windows are fine.
  My last option; the kitchen.
  I steel myself for what's coming. With caution, I raise myself back to a standing position, and slowly, step by step, walk to the doorway.
  One deep breath, before I lunge in, flicking the lights on and waving the gun wildly around the room.
  There's no one inside, and the window is...
  Solid.
  "You forgot your own room." I hear from behind, before a whack resounds, and a sharp pain runs through my head. The room spins, and everything quickly turns to black...