GI planet migration from its birth by disc fragmentation at 100 AU into the inner disc. Top: disc surface density Σ(R) at several different times, with the respective positions of the planet shown as vertical lines. Bottom: disc temperature, dimensionless cooling time, β, Toomre parameter, Q, and Toomre mass, M_T (initial fragment mass), at t = 2 × 10⁴ yr. The disc is GI unstable beyond ∼100 AU and is capable of hatching gas giant planets.