Dr. Lawrence Grady is the father of Kevin and Dillon who worked as a physician in the memory department of the Summerholt Neurological Institute in the WB Television series Smallville.
He served as the main antagonist in the Season Four episode "Blank".
Lawrence Grady lived in Smallville together with his two sons Kevin and Dillon. One day while hunting with his sons in the woods, Lawrence accidentally shot and killed Dillon. Kevin had witnessed it and in order to prevent the truth from being known, Lawrence took him to the Summerholt Institution and subjected him to a memory alteration treatment in order to make him believe that he had killed his brother.
The treatments had the side effect that Kevin acquired the ability to emit from his fingertips a flash of green light that could erase a short period of a person's memory.
When Kevin accidentally erased Clark Kent's memory causing him to have total amnesia, Chloe looked after him and looked into Kevin's background. They found Kevin's ID at the Talon and traced it back to the Grady residence.
Kevin returned to his family home to pack his bag when his father finds him. Kevin explained that wherever he was, they turned him into a freak and he knows that he couldn't stay because of what he did, so he was leaving for good.
Lawrence argued that the therapy was not yet finished, but Kevin zapped his father's memory and leaves. When Clark, Lois, and Chloe arrived looking for Kevin, Dr. Grady first told them that Kevin was out of town but then admitted that Kevin was at the Summerholt Institute for memory treatment.
He told them that Kevin had accidentally killed his brother Dillon while hunting, and that he was trying to get the tragedy erased from Kevin's memory.
Chloe sneaked into the Summerholt Institute and found video files of Kevin's treatment. Lawrence found Chloe searching his computer and captured her. He tied her up and connected her to the same medical equipment. as he had done with Kevin.
Chloe begged to be let go and promised not to tell anybody what really happened, but Dr. Grady was ready to wipe her memory clean. When he prepared to erase her memories, Kevin entered the laboratory and confronted him about his lies and attacked him.
Dr. Grady knocked him out that he fell over a table and banged his head against an edge what rendered him temporarily unconscious. He began the treatment on Chloe. When Lawrence finally started the procedure, Clark came into the laboratory and intercepted the beam that was intended to erase Chloe's memories.
Clark thereby got his own memories back, but overloaded the machinery so that it collapsed. Lawrence was hit and knocked out by a green beam of energy emitted from some bursting machine parts. After Clark had freed Chloe, Dr. Grady was taken into custody by the police.