The Gideon is a satellite owned and operated by the Cahill family. The satellite is named for the family's founder, alchemist Gideon Cahill. The Gideon is outfitted with spy capabilities and was used for global positioning and for teleconferencing between members of the family. However, it had a weakness to sunspots.
The satellite was purchased by Madrigal Amy Cahill, who had become the leader of the Cahill family after winning the Clue Hunt and inheriting the fortune of her late grandmother, Grace Cahill, the previous family leader. Another Cahill, Ekaterina Sinead Starling, worked on the satellite, including trying to get rid of the sunspot weakness.