The Rotting Deep (audio story)

 was the first story in the audio anthology Water Worlds produced by Big Finish Productions. It was written by Jacqueline Rayner and featured Colin Baker as the Sixth Doctor, Bonnie Langford as Melanie Bush and introduced Ruth Madeley as new companion Hebe Harrison.

Publisher's summary
A mysterious SOS summons the Doctor and Mel to an oil rig in the North Sea where a dwindling group of survivors awaits rescue from a lethal menace. One of their number is Hebe Harrison, a wheelchair-using marine biologist who is definitely more than she seems. Can our heroes escape the rig? And just what is killing off the rig's beleaguered crew?

Plot
to be added

Cast

 * The Doctor - Colin Baker
 * Melanie Bush - Bonnie Langford
 * Hebe Harrison - Ruth Madeley
 * Jonah Strong - Rove McManus
 * Sky Bennett - Mandi Symonds
 * Carl Price / Dean - Charlie Tighe
 * A.M. 'Ancient Mariner' - James Smillie

Continuity

 * Hebe studied at the same university professor Evelyn Smythe used to teach. Hebe talked fondly of Evelyn and the former companion was the reason why Hebe was able to send a S.O.S. to the Doctor. (AUDIO: The Marian Conspiracy et al)