- You may be looking for the short story.
A séance was a way of contacting what appeared to be ghosts. Using Gwyneth's clairvoyant connection to the Rift, in 1869, Gwyneth, the Ninth Doctor, Rose, Charles Dickens and Sneed held a séance to speak to a gaseous Gelth. (TV: The Unquiet Dead)
In 2010, the psychic Evadne Wintergreen was hired by the House of the Dead ("the most haunted pub in Wales") to host a séance in the last day of the business. Her presence helped summoning Syriath, an ancient entity trapped in the Cardiff Rift, able to bring back the dead, among which Ianto Jones and his father. (AUDIO: The House of the Dead)