Singularity

You may be looking for the audio story.

A singularity was a point in space-time which could exist only inside a black hole. (TV: The Three Doctors) Romana described it as a mathematical point with no dimensions. (TV: The Horns of Nimon)

When Omega was transported through a black hole into the anti-matter universe, he gained control of the singularity and used its vast power to create his own world. (TV: The Three Doctors)

The smallest Parablox set included 35 bricks that could be assembled into a pocket-sized naked singularity. (PROSE: The Book of the War)

In 2003, the Seventh Doctor used a singularity which generated X-ray pulses to sterilize Agent Yellow, saving humanity at the cost of killing millions. (PROSE: Eternity Weeps)

In 2157, IMC planned to use controlled singularities to remove Lucifer's outer atmosphere, allowing them to mine the heavy elements at its core. (PROSE: Lucifer Rising)

On Farside Station in the late 22nd century, Professor Deschamps experimented with artificial singularities in an attempt to develop a singularity bomb. (PROSE: Fear Itself)