You'll have to help the Minutemen faction retake their old stronghold (known today as Fort Independence) - The Castle - to catch a glimpse of this crafty little secret, but it's worth every second. As a direct homage to the famous Boston-born writer Edgar Allan Poe, you'll find the remains of a poor man in the bowels of the fort; chained up within the crevice of a brick wall and surrounded by bottles of Amontillado. Go and read Poe's 'The Cask Of Amontillado', and you'll discover the gruesome fate that befell this poor sod.