In 1958 Morton Smith, an American scholar of ancient religion, was cataloguing the library of the monastery of Mar Saba in the Judaean desert. In the back of a printed edition of the letters of Ignatius, published in 1646, he found two and a half pages of Greek written in by hand in what looked like an eighteenth-century monastic script.
The text presents itself as a letter from Clement of Alexandria, writing near the end of the second century, to someone named Theodore. It addresses a group called the Carpocratians, who it says have got hold of a version of the Gospel of Mark and corrupted it. In the course of the argument the letter quotes that gospel, describing a longer or secret Mark used at Alexandria for those being initiated, and it gives two passages from it that appear in no other source. One describes Jesus raising a young man from a tomb, in language close to the raising of Lazarus in John, and the young man afterwards coming to him by night wearing a linen cloth.
Smith photographed the pages in black and white and published his study of them in 1973. What he had found, if it was what it appeared to be, was evidence of a second-century Alexandrian tradition attested nowhere else, and a version of a canonical gospel that had left no other trace.