Norman Leith was a radical architect who was depressed and suicidal until his disappearance in 1983 (2 months after the disappearance of Max Shea). Considering his character, the disappearance came not as a surprise, but New Frontiersman find the connection between it and Shea's and the other creative figures who also disapperance around the same time.
Apparently he was taken to the Veidt's island to work on a secret project with the other vanished people. Months later a Pyramid Deliveries ship came to take them and Max Shea noted that even he was smiling. He was killed when the ship exploded, leaving nobody alive to talk about it.