The Echo Cave

I bolted down the gravel drive straight toward the black metal mailbox sitting atop its cedar post! The hinged door hung cracked open, revealing a shadowy cylinder ripe for an ambush. Without braking, I launched myself right inside! My round belly squeezed past the rim with a loud screech, bumping straight into a thick rolled-up catalog. The sudden jolt rattled the whole box, flipping the squeaky red metal flag up with a sharp clang! Snug inside my new iron fortress, I let out a wet, bubbling roar, laughing as the curved metal walls bounced the noise right back into my face.