The Pyrovile pod was an escape pod used by the Pyroviles. It was made of rock. The Tenth Doctor suggested it was a gene bank.
The surviving Pyroviles from Pyrovillia fled to Earth when their planet mysteriously disappeared. It crashed into the surface of Earth so violently, the Pyroviles were ground into dust inside the pod, which later became a control centre for Vesuvius, where they began to reconstitute themselves. The Pyroviles used the pod to house their control matrix to harness the power of the volcano so that they could convert the population of Earth into more Pyroviles.
The Doctor and Donna Noble discovered the pod and were forced to hide inside. The Doctor realized that the only way to stop the Pyroviles was to invert the control matrix and cause the eruption of Vesuvius which was a fixed point in time. Together, the Doctor and Donna triggered the eruption, destroying the Pyroviles and Pompeii. The pod was tough enough to withstand the immense power of the volcano, blasting out of the eruption and onto the ground nearby, allowing the Doctor and Donna to survive the blast. The two quickly fled the pod as it was consumed by the approaching ash cloud. (TV: The Fires of Pompeii)
