The Doctor is back in the lives of Grant, Lucy, and their daughter, Jennifer! He’s on a mission to find the other three alien gemstones, siblings of the one that gave Grant his superheroic powers – and only Grant can lead the way! Following the gems’ trail through time, the four ended up battling the fearsome entity known as THE SMOKE, and freeing a world from the Harmony Shoal – reclaiming two gems in the process. With just one gem left to find, the team fell right into the laps of the Sycorax! Now they’re trapped aboard the Sycorax flagship, as a doomsday weapon begins to fire...!