Professor Bernice Summerfield and the Crystal of Cantus (audio story)

 was the twenty-eighth Bernice Summerfield audio story released by Big Finish Productions. It was the fifth and final story of the sixth season. It was told unconventionally through voice-overs and flashback-style point of view scenes.

This story also featured the Cybermen, as the cover art (and dialogue in-story) indicates Cybermen of The Tomb of the Cybermen-era. It is notable for its gruesome revelation of how the Cybermen create Cybermats: from babies.

The story reveals Irving Braxiatel's motivations and manipulations (particularly of Jason Kane) that began in the 2003 story The Mirror Effect.

Publisher's summary
Fabled crystals from long-dead civilisations. Jason Kane blundering into situations out of his control. Entombed Cybermen waking from a century-long sleep. It's all in a day's work for Professor Bernice Summerfield. Armed with her endless supply of witty quips and penchant for alcoholic beverages, she'll find the Crystal, rescue Jason, destroy the Cybermen and be home in time for supper.

Except, this time, it's different. This time, as the saying goes, it's personal.

And, after this adventure, things will never be the same again.

Plot
to be added

Cast

 * Bernice Summerfield - Lisa Bowerman
 * Jason Kane - Stephen Fewell
 * Ronan McGinley - Nicholas Briggs
 * Irving Braxiatel - Miles Richardson
 * Joseph - Steven Wickham
 * Peter Summerfield - Thomas Grant
 * Parasiel - Paul Bryant
 * Commander Hallan - Michael Cuckson
 * Babs - Katarina Olsson
 * Jack - Toby Longworth
 * Thesanius - Gary Russell
 * Cassus - Joseph Lidster

Music

 * Jason sings "It's a Long Way to Tipperary".

Species

 * The Cybermen create Cybermats from babies.
 * The Galyari perform Macbeth on Berkoff IV.
 * Parasiel mentions the Draconians, the Mim, and the Sunari as potential threats to the Collection.

Continuity

 * This story continues Braxiatel's manipulation of Jason that started in AUDIO: The Mirror Effect and his motivations in AUDIO: Death and the Daleks.
 * Braxiatel's reasons and motivations for this are further explored in AUDIO: Mindbomb.
 * Benny refers to the events of TV: The Tomb of the Cybermen and states the Cybermen have tombs across the galaxy.
 * Benny corrects Parasiel in that the Cybermen came originally from Mondas, not Telos. She gives a potted history of the origins of the Cybermen: they were dying and started replacing their parts (TV: The Tenth Planet; AUDIO: Spare Parts)
 * Thesanius tells Jason, in a message to Bernice about the crystal of Cantus, to meet him on Garazone. (AUDIO: Sword of Orion)
 * The crystal is the same as on the Coronet of Rassilon. (TV: The Five Doctors)
 * Benny has met the Cybermen before. (AUDIO: Silver Lining)
 * There is a flashback to a younger version of Braxiatel on Gallifrey where Darkel is asking for him. (AUDIO: Weapon of Choice, et al)
 * Jason's memories of Verum were blocked by Braxiatel. (PROSE: On Trial)