It's twilight outside, not yet COMPLETELY dark, I can make things out quite clearly - I peer out of the sliding doors and I can see nothing, but the cat is still at it so finally I get up and take a closer look through the door. Nothing. I go next door and peer out the window, hands cupped against the glass to cut out the reflective glare from the lights inside.
And the pile of blue tarp bundled into the chair outside the window suddenly lifts a sharp pointed possumy nose at me.
Okay, my heart is still racing. The possum is now gone, but I keep having visions of my blue tarp coming to life. I'll dream of possum-hatching tarpaulins tonight.