Gregory Belson and Victor Fries were good friends in college. The two worked together on cryogenics research in the Gotham based company, Gothcorp. However, following Victor's tragic transformation into the villain Mr. Freeze, Belson cut off all contact with his old friend. Later, Belson received inside information on a new miracle drug. The incompetant doctor invested all of his money to see it put on the market. This proved to be a waste when the FDA discovered side effects and put it on hold. Gregory found himself sinking in debt. He constantly begged his stockbroker to stall the tax collectors so he could get the money, but this proved futile.
Belson's luck took a strange turn when he reunited with his old partner, Victor-now known as Mr Freeze. Victor tried to persuade Greg to operate on his cryogenically frozen wife Nora, who was coming close to dying of her disease. Doing research, Belson discovered that the only way to save Nora was through an organ transplant. Freeze then struck the perfect deal: If Belson could find a suitable donor for Nora and perform the operation, Freeze would give him a huge supply of gold he discovered in the arctic. Belson, a greedy, desperate man, decided to go through with it. The two looked for suitable donors at the hospital and discovered that the only one who had Nora's bloodtype was a live one-Barbara Gordon. They located Barbara at a nightclub, kidnapped her, and brought her to an abandoned oil rig where Freeze was making his home.
Unfortunately, Barbara (who was really Batgirl) proved harder to contain than they anticipated. She escaped from her room, and the scheming duo(Belson and Freeze) spent much trying to keep her from escaping.
Later, Belson made a big mistake. He called his stockbroker (Dean Arbagast) to assure him that he'd have his debt paid in time, but what he didn't realize was that Batman and Robin were at Arbagast's house. A fog horn sounded during the call, the heroes heard it, and this alerted them that the villains were hiding at the harbour.
Eventually, the time came for the operation. But Batman and Robin arrived, and Barbara escaped before it could begin. While trying to recapture Barbara, Belson goofed up yet again when he set fire to the base. Panicked, he told Freeze they have to leave, but Freeze angrily yelled at his friend, telling him they couldn't leave until Nora was saved. Belson pushed Freeze under debris and tried to escape on his own, making off with their motorboat.
Ultimately, the doctor's stupidity proved his demise. Belson drove frantically around the burning oil rig to escape-right into the path of a falling landing deck dislodged by Robin's take off of the batplane. Belson had enough time to look up and scream before the debris crushed him, bringing a swift end to his troubles.
Afterward, it's assumed that his involvement in Barbara's kidnapping was revealed. However, seeing as no one witnessed his death, it is unknown if Gregory is officially pronounced dead by the public.