Neural relay

Neural relays are devices used in the 51st century to let people send "Thought-Mail" by Point-And-Think Technology. Sometimes, if someone dies, their consciousness may still leave an imprint in the neural relay. Using its comms device, the Data Ghost is able, for a short time, to talk to other people, before deteriorating, starting to repeat itself.


 * Miss Evangelista's data ghost wanted to talk to Donna, but deteriorated to repeat "Ice Cream."
 * Proper Dave's, "Hey, who turned out the lights?"
 * Other Dave's "We should go, Doctor!"

Anita was killed by the Vashta Nerada, but had no obvious Data Ghost, as the Vashta Nerada had learned to talk through the neural relay.