The provided excerpts from Robert Ludlum’s The Sigma Protocol follow two parallel narratives involving a vast, secret organization established during World War II. Ben Hartman, a man grieving his twin brother's supposed death in Switzerland, finds himself suddenly thrust into a desperate flight for his life after realizing his brother's demise was faked, uncovering the existence of a shadowy cabal known as Sigma A.G. Concurrently, Special Agent Anna Navarro of the U.S. Department of Justice is assigned to investigate a suspicious pattern of deaths among older men associated with the mysterious "Sigma files," leading her across continents.