Geiger was a mortal who joined the Watchers solely to discover the secret of immortality. During his time with the group, he discovered the legend of the Methuselah Stone. Most of the crystals that formed the Stone were kept in the Director's Gallery at Watcher Headquarters, they had been taken from the body of the Immortal, Luther, but the Immortal Amanda still held the last piece. Upon reporting his discovery to his supervisor, Geiger was reassigned from the field to Research by Nathan Stern.