Dr. Keel investigates the disappearance of one of his patients' husbands, a noted scientist working on a hush-hush government project. Suspecting that there's dirty work afoot, Steed convinces Keel to impersonate the missing scientist. Complicating matters is the fact that one of the villains' accomplices is an anesthetist at the hospital where an injured Keel is brought for treatment. Written by Terrence Feely, "Nightmare" was originally telecast live on January 28, 1961. ~ Hal Erickson, Rovi