Invocation (audio story)

 was the second story in the audio anthology, Encounters, produced by Big Finish Productions. It was written by Roy Gill and featured Jemma Redgrave as Kate Stewart, Ingrid Oliver as Petronella Osgood, James Joyce as Josh Carter and Ramon Tikaram as Vikram Shindi.

Publisher's summary
It's Hallowe'en, and Josh finds himself at a party where phantoms are becoming all too real. Osgood is working late and hears a voice from the skies making strange incantations. The next day, Kate has gone missing in the Scottish Borders, and the team head north to investigate. Ghosts from the past are haunting UNIT, and now they threaten the whole world…

Plot
On Hallowe'en, Kate goes to Scotland to find out why UNIT has held onto former research facility Ealdon House and to ensure that nothing has been left behind. The caretaker, Donelly, gives her a tour and she realises that she came to the house with the Brigadier as a girl and that she and Ben had a rhyme about a Grey Man. She looks around the house at night and, in the gallery, sees him approach her with his long fingers.

Osgood stays late at UNIT HQ with Corporal James Morley and picks up a transmission from a 1960s satellite which should have run out of power long ago. Originally in English, it changes to an archaic Latin invocation of a spirit. The next day, Josh tells her about how everybody at Phoebe's Hallowe'en party saw a Grey Man that he could not and Osgood finds that Phoebe's house used to be a television station. The two of them fly to Ealdon House after Kate fails to check in and, on the way, Osgood finds that some of the information on the research there is missing.

Kate learns that Donelly served in the British Army, but she avoids any and all questions put to her about it. Osgood becomes suspicious of Ben upon learning that he works in computer forensics, meaning that he likely has the skills to remove the data from UNIT's system, and later sees the Grey Man. She realises that Josh cannot see it because of the plastic skeleton that the Nestenes left him with. He smashes a window with a wooden panel to change the resonance and get rid of the Grey Man and finds a computer printout of the invocation.

Shindi has his men ready to evacuate the area around Phoebe's house if there is further activity. When spectres begin appearing, civillians and the soldiers alike are terrified the closer they get to the building. The phenomena begins to spread and Morley despairs. Upon hearing of these, Osgood determines that infrared sound is being used to create hallucinations but says that the satellite cannot be so advanced. Josh lets Shindi know and passes on her suggestion that the soldiers put on particular helmets.

Kate confronts Donelly about the records that she has managed to find in storage; she was kicked out of Ealdon House after her research into infrared sound was shut down by the Brigadier. Kate holds her at gunpoint and demands that she works to stop what is happening in London despite her insistence that it has nothing to do with her. Donelly says that she does not recognise most of the code but that the invocation was chosen at random from a book on demonology. Osgood manages to access the satellite to put a stop to the spectres and realises that an alien race must have taken the message as an invitation.

The Grey Man appears to Donelly alone and she runs from it, throwing herself through a window. Kate gives Osgood a message to send out to the satellite saying that they have leave to walk the Earth until the day that Donelly, who summoned them, dies. The phenomena ends.

Cast

 * Kate Stewart - Jemma Redgrave
 * Osgood - Ingrid Oliver
 * Captain Josh Carter - James Joyce
 * Colonel Shindi - Ramon Tikaram
 * Phoebe Breckenridge - Karina Fernandez
 * Alice Donelly - Lucy Fleming
 * Ben Donelly - Matthew Cottle
 * Corporal James Morley - David Jonsson
 * Satellite Voice - Barnaby Edwards

Continuity

 * Sam is missing. (AUDIO: The Dalek Transaction)
 * Josh cannot see the ghosts due to his Auton physiology. (AUDIO: Bridgehead, Armageddon)