The Planet of Oblivion

The neutral ground of the usually lush and beautiful Ursulonamex, known as The Planet of Oblivion, is now scorched and charred. This is where the Darksmiths met their clients to discuss the Eternity Plan, but there is no sign of the clients now, nothing to suggest who they were... as though the mysterious clients have made sure of it. The Doctor and Gisella learn from the few survivors of the Rain of Fire, and that the only clues there might be of what happened could be stored in the observation stations in orbit round the planet. Do any of the observation stations still exist? Are the Doctor and Gisella as alone on board as they think? Who are the Dravidian Hive and are they as benign as they seem...? What is a Dreadbringer?