Doctor Who: Rutans vs Sontarans: Betrayal at the House of Sontar

There are many stories of the Sontaran-Rutan war. But one hidden thread has yet to be revealed. A tale told across millennia. From before the war to its possible end. As the Doctor is about to discover... On the run from the mysterious organisation called Division, the Doctor has come to the planet Sontar - home of the Kaveetch Empire and their armed forces, the Sontarans. She wants sanctuary... and she's offering the secrets of the Time Lords in exchange. But with the whole of time and space up for grabs the stakes are high. Can everyone on Sontar be trusted?