Pat Hingle plays a Mike Royko-style newspaper columnist, (he's called "Mike Decker"), who has championed Richard Kimble's innocence. Kimble thinks the one-armed man might be in Chicago and contacts Decker to get his help in finding him. Decker sees a Pulitzer Prize in helping to prove Kimble's innocence and agrees to help. What Kimble does not know is that Decker is more mercenary than he realizes: he could also win a Pulitzer for arranging Kimble's capture, as his editor reminds him. Gerard then intervenes and sets up a trap through Decker.
In fact the one armed man is in Chicago. He's played by Burt Lancaster's former stand-in, Bill Raisch, who has quite a history: http://www.imdb.com/name/nm0707199/bio?ref_=nm_ov_bio_sm
Per Ed Robertson's book on the series, "The Fugitive Recaptured"), Quinn Martin wanted the one-armed man to remain a possibility, rather than an established fact: "kind of ghost-like, mystic: is he real/ isn't he real?" That ended when we catch a glimpse of the one- armed man in "The Girl From Little Eqypt", (the same glimpse that hunts Kimble throughout the series and will be part of the into from the second season on). In this episode they confront each other for the first time and Raisch has his first of few lines in the series. His appearances will be rare for the first three seasons, (six of his ten spots are in the final season). But at least we know he's real.