The Sign of Diolyx was the fourth and final story of the first series of the Big Finish Productions range of audio dramas. It was released in 2002, consisting of 3 episodes (all on 1 CD).
- John - Nicholas Young
- Elena - Helen Goldwyn
- Paul - Daniel Wilson
- Voice of TIM - Philip Gilbert
- Mr. Hardy - Gareth Thomas
- Alison - Clare Buckfield
- Rev. Jane Green - Louise Faulkner
- Diolyx - Toby Longworth
A new TP is breaking out, but something is horribly wrong. John and Paul travel to the Welsh village of Llan-y-Gwyliadwriaeth, but find that a psi dampening field is hampering their investigation and that young Alison Hardy has no intention of embracing her dormant powers.
Meanwhile Tim discovers an energy signature connecting the village with a mysterious ship in hyperspace, Against Tim’s better judgement, Elena goes to investigate and finds herself trapped with a ravenous alien entity.
What is the connection between the local vicar and the coven in Alison’s dreams? What links and ancient stone circle and the ship in hyperspace? Who or what is Diolyx?
The Tomorrow People find that they have stumbled upon an ancient evil. An evil that us about to be unleashed upon the world.