Little information is known about Ted Castle. He was married to Alyssa Moy-Castle which was Reed Richards' ex-girlfriend. Years after, he and Alyssa created a world for the replacement of the original one for their theory that Earth will soon be doomed and there is no solution to stop it. This world is called Nu-World. However, Ted is aware that Alyssa still loves Reed. Ted is as intelligent as his wife and very rich, but although he is wealthy, his wealth is still not enough to supply the needs for their project Nu-World. Like his wife and Reed, CAP is also programmed not to hurt him.
Ted did not have the good intentions that he outwardly displayed, fooling even his wife into believing him to be a humanitarian. Secretly, Nu-World was for the rich and powerful. Ted and the other benefactors planned to leave almost everyone else on Earth behind to die so they could recreate the world in their image. His plan was foiled after Alyssa told this to the Fantastic Four and they used Nu-World as a location for six billion refugees from a dying future.
Upon the arrival of the New Defenders, Ted had a robot army prepared to take them into custody for their removal. So they could not get any help, he destroyed the portal off of the planet. He planned to take the remaining heroes to Nu-Moon and then figure out a way to remove all the people from his world. When they refused to cooperate, Ted ordered his robots to detach the core of Nu-World, which would turn the planet into an uninhabitable world of ice.
With the help of Alyssa Moy, Hulk Jr. remotely activated the self destruct mechanism of Nu-Moon, thus leaving Ted no choice but to call of his robots and leave the world habitable for his sake. Ted swore that he would find a way to remove them from his planet. The solution came to him in a dream when a mysterious woman from that dying Earth claimed she wanted her children back.
The woman was Mother Earth herself, Gaea, driven insane by the lack of life on her planet. Ted sided with her because they had the same goal: get the people off of Nu-Earth. Gaea and her Hysteries were eventually defeated and it would seem that Ted and Alyssa became reconnected when they teamed up to try and stop Ego the Living Planet from destroying Nu-World.
After some time, the sun collapsed in on itself, turning into a black hole and accelerating time rapidly. In this time, the people of Nu-World lost their will to live and war and chaos ensued. Lightwave and Alex Ultron of the New Defenders took over control of the planet. Ted and Alyssa became outlaws stuck on the planet because the portal to escape was broken.
Ted had hoped to find Reed Richards, but instead got his genius daughter Valeria. She provided Ted with a power source capable of fixing the portal and steering Nu-World away from the black hole. He remained behind with his creation and his fate and Nu-World's remains uncertain.