What if a 300-Earth-mass gas giant orbited a Sun-like star at 5 AU, embedded in a vast ring of 200,000 particles spanning 4.5 to 5.5 AU? The planet's gravity shepherds the debris, ejecting some particles to interstellar space, driving others into collisions with the planet or star, and trapping material at the L4 and L5 Lagrange points. This mirrors how Jupiter may have sculpted the early asteroid belt and how Saturn's moons confine its rings. Debris rings around young stars — seen in infrared by ALMA — are thought to be the birthplaces of planets. The scenario models the violent, messy intermediate stage between a protoplanetary disk and a mature planetary system.