Forced to work together to save the universe from collapsing, the Doctor, the Master and Tegan use the Master's Tardis to travel to a giant satellite dish on Earth. Meanwhile Adric and Nyssa are taken to safety by the mysterious Watcher.
With the universe collapsing, the Doctor forms an uneasy alliance with the Master to save it. In case all does not go well, the Watcher takes the Doctor's companions to a safe place, but his plans for them don't stop there. The one hope for all lies back on Earth.—statmanjeff