An extremely intelligent and thoughtful man, Inspector Sampson of Scotland Yard was the leading investigator in the murder of Michael Radcliffe, a crime for which his own brother Geoffery Radcliffe was convicted. When Geoffery Radcliffe escaped from prison under mysterious circumstances shortly after being visited by family friend Dr. Frank Griffin, Sampson, no fool, realized instantly how the prisoner had escaped. Sampson knew that Frank's late brother Dr. Jack Griffin was the original Invisible Man, for he had followed the case those many years ago. Now, Sampson realized, Jack's brother Frank had used the infamous duocane formula to make Geoffery Radcliffe invisible to allow him to escape from prison.
As he had with Michael Radcliffe's murder, Sampson was the leading police official in charge of tracking down and apprehending the fugitive Geoffery. Knowing he was dealing with an Invisible Man, the shrewd and resourceful Inspector devised many means of rendering Geoffery visible to allow his men to capture him, including smoke and nets. In the meantime, Sampson began to suspect that Geoffery was innocent of his brother's murder when the surviving Radcliffe brother began targetting his cousin Richard Cobb for seemingly no reason. Sampson's suspicions eventually paid off, as after falling out of a coal cart during a fight with the invisible Geoffery at the Radcliffe Colliery, Richard confessed on his deathbed that he was Michael's real killer.