Tallus

Tallus is an elderly man who lives in the city of Weld. He is Southwall's healer and he worked closely with his assistant and apprentice Sholto examining skimmers and their anatomy. It was Tallus who devised the plan to use light to fend off the Skimmers, although th Warden, set in his ways and fearing change, would not allow him to test the invention. Tallus, however, opted to test his theory anyway, with success, much to the Warden's grievances and anger. Furthermore, with Sholto, Tallus had many theories about the Skimmers and their origin,  eventually leading to Sholto's discovery of how they had rapidly evolved from clinks through exposure to jell.

The Three Doors

 * The Golden Door
 * The Silver Door
 * The Third Door