Bernice Summerfield: The Tartarus Gate

In 2006, Bernice Summerfield: The Tartarus Gate was released by Big Finish Productions.

Cover blurb
Benny is missing, having not returned from a dig. Kidnapped expertly. Removed from time and space completely. Jason, of course, uses every means at his disposal to find her. But resources are limited: the Braxiatel Collection has its own far more urgent problems.

Then he receives information on her possible whereabouts, from a benevolent religious order known as the CroSSScape.

Why is Benny on the planet Cerebus Iera, a planet on the cliff-edge of the universe? A planet that is known to be violent, dangerous, and uninhabitable. A planet rumoured to have links to the Tartarus Gate, the mythical gateway to hell.