Teleportation feed

A teleportation feed was a device associated with certain forms of teleportation, including those effected through 5,000 degrees of heat. As the Ninth Doctor deduced, Cassandra O'Brien.Δ17 kept a teleportation feed hidden within an Ostrich egg aboard Platform One. Upon finding the device, the Doctor was able to reverse the feed, returning Cassandra to the observation deck. (TV: The End of the World)