Along with Ashley Moby and Janine Gilbert, Joe was taken by SenéNet and turned into a drone by Dr Ingrid Krafchin to be used by Cellian and Ciara. After the destruction of Senénet, though, the twins came to regret what they had done for the company and took care of the teenagers. (PROSE: Business Unusual)
Trey Korte was still looking for Hambidge four years later when he met the Sixth Doctor and Mel again. He was captured by the Magnate, who wanted to use his psychic powers. He found himself being held by Cellian and Ciara, who also had Joe Hambidge with them. Joe apparently had no memory of Korte as a result of the brainwashing he and the other teenagers had undergone.
What Korte did not know was that Hambidge did remember their time together. His mind, though, had been made unreadable telepathically from the procedures done to him by Senénet and left him emotionally stunted. After a Cylox invasion was stopped by the Magnate, he continued to feign ignorance so Korte could move on with his life. (PROSE: Instruments of Darkness)