"Back to Methuselah" (A Metabiological Pentateuch) is a 1921 series of five plays and a preface by George Bernard Shaw. The five plays are: "In the Beginning: B.C. 4004" (In the Garden of Eden); "The Gospel of the Brothers Barnabas: Present Day"; "The Thing Happens: A.D. 2170"; "Tragedy of an Elderly Gentleman: A.D. 3000"; and, "As Far as Thought Can Reach: A.D. 31,920". The plays were published with a preface titled The Infidel Half Century, and first performed in 1922 by the New York Theatre Guild at the Garrick Theatre.