The Doctors investigate, while UNIT headquarters faces an attack by shapeless blob-like creatures. The First Doctor realises that the black hole is a bridge between universes, so they allow the TARDIS to be swallowed up by the energy creature, finding themselves in an antimatter universe created by the legendary Time Lord Omega, a solar engineer who created the supernova that powers Time Lord civilisation, but which also supposedly killed him. In fact, he remains trapped in his antimatter universe, whose reality is maintained by his will alone.