The first time that Big Finish has been able to use the Sontarans in an audio drama (and the first time the Fifth Doctor has tangled with the monsters). This drama is a comedy-horror story that takes the TARDIS crew to the monastery planet of Samur, not too long after the Sontarans have razed it. Soon, Nyssa contracts a mysterious infection, and the Sontarans land on the planet, their usual trigger-happy selves. And something else is on the planet, something eager to kill...