A Ribbon on the Line

I spotted a mysterious gap right between two heavy hardcover books and couldn't resist rolling straight through! My front buffer nudged right against a stray spool of blue ribbon, sending it wobbling ahead like an extra-special evening parcel. The narrow passage curved around the table leg just like a hidden tunnel, making my wheels clatter briskly over the wooden floorboards. I was going a bit fast and nearly overshot the junction, bumping gently into a stack of folded envelopes. But with a careful reverse and one last determined push, I parked the ribbon neatly in the corner depot.