It's true that the idea of secrets in stones may have lost some of its mystery, if only because we have come to discover that wonders are often concealed in the most unexpected as well as the most ordinary.

The arrival in Dublin last week of a large crate containing, along with about 125 pages of papyrus mounted between glass, an object resembling a sod of turf, is an exciting example of the remarkable contained in the humble. Except that the humble "sod" in question, now

housed at the Chester Beatty Library in Dublin, is not turf; it is the shape papyrus assumes when its fibres become matted and tangled. The block is a major text of a once-great world religion.

Had Christianity failed, the Manichaean religion - devised in the 3rd century and based on a powerful central thesis, the battle between good and evil in man and in the cosmos itself - could have survived as a major world religion.

Indeed, for some nine years prior to his conversion to Christianity, St Augustine was a follower of the teachings of the 3rd-century Persian prophet Mani (known as Manes to the Greeks and Romans). This holy man of noble birth believed his life's task was to amalgamate the best elements of all religious teachings, including those of Christ and Buddha. He won many converts and was successful through the Roman Empire, Africa, India and China.

Eventually, the Zoroastrian priests had enough, and he was flayed, crucified and stuffed.

It may initially be difficult to associate the one-time potential of a now-lost world religion with the turf-like block newly arrived in Dublin. Despite its somewhat unpromising appearance, Beatty purchased the then larger block of solidified papyrus from a dealer in Cairo in the late 1920s, suspecting it was an important theological document charting the origins of civilisation itself. Its age attracted him and by that time he had also secured two very important buys, the Biblical papyri - on permanent display in the Chester Beatty Library - and the Egyptian Love Poems. His interest is itself fascinating, as collecting papyri is a highly specialised pursuit and the papyri themselves lack the physical splendour of illuminated manuscripts.

The mass or block of papyrus consisted of five books, the Manichaean Psalm Book, the Kephalia or Instructions of the Teacher, Homilies, an unnamed text, and the Synaxeis or The Living Gospel of Mani, all written in Coptic on papyrus. Having been buried in the sand on the banks of the Nile, a combination of the centuries, moisture and natural salts leached from the earth had caused the books to fuse together. The block, now extending to 665 separated pages, all of which are in Dublin, was discovered within four feet of the flood water of the Nile, and so had come that close to being lost forever.

It remains unclear exactly when it was found but it is known that antiquities dealers in Egypt had crudely broken or separated the block into several sections - much as book dealers do now with atlases and maps - and tried selling it on the open market. At first, experts considered the fibrous mass to be beyond restoration. But gradually conservators began peeling away layers of papyrus. Following the acquisition of one section of the Kephalia by the Egyptian Museum in Berlin, Beatty was offered a section, possibly the Homilies, for examination.

By nature a cautious buyer, he was wary of the risk but decided to take it. On his return to London, he went to the British Museum and its conservators attempted to separate some of the leaves. They managed to peel off a few pages, but felt it too difficult an undertaking. However, there was a craftsman in the Berlin Museum capable of separating the books. Hugo Ibscher, a highly skilled conservator though not a scholar, had "a great hand, a great eye, and great patience" according to Charles Horton, curator of the Western manuscripts in the Chester Beatty Library.

Though a private collector, Beatty was in the unusual position of being able to secure the services of Ibscher through the British Museum. He paid for the German expert to be sent to London on secondment. Initially, Ibscher worked in London, but then, as the size of the project became clear, he returned to Berlin, bringing the text with him. By the mid-1930s, he had freed some 31 pages of the book known as the Homilies. (These were sent to Beatty in London and were in the collection when he shipped it to Dublin on moving to Ireland in 1950.)

In Berlin, Ibscher worked on, freeing an average of seven pages a month from the Psalm Book and the Kephalia. Then war broke out, and the remaining part of Beatty's manuscript, along with thousands of other museum and art works, were stored in a vast bunker under Berlin Zoo.

In 1945, Ibscher, who had stayed in Berlin, took some sections of the Beatty manuscript with him to Bavaria, probably for safety. The pages he had worked on were later acquired by the British Control Commission and returned to Beatty. The rest of the manuscript was confiscated from Berlin and taken to St Petersburg (then Leningrad) as part of war reparation. Beatty accepted he would never see these texts again.

In 1958, though, in a gesture of goodwill, the Soviet Union returned it to East Berlin.

More pages were to find their way back to Beatty as Ibscher's son Rolf, a scholar, had continued his father's work. In 1961, as the Wall became a reality, Dr Otto Finchow, then keeper of Egyptian antiquities at the East Berlin Museums, having decided to defect, saw the Beatty manuscript as his passport to the West.

Beatty was unhappy at the exploitation of his property. The remainder of the text stayed where it was, still compacted in turf sod form, in Berlin. Beatty died in 1968, his collection the property of the Irish people. For almost 30 years, though, little appears to have happened to the texts still in Germany. Written around 400 AD, all of these books, including the Synaxeis, amount to the major source of the Manichaean religion. With the return of the block itself, with a possible further 80 pages to add, and the rest of the Synaxeis, to Dublin, the original Chester Beatty Manichaean texts are re-united for the first time since he purchased them in the 1920s. According to Horton: "These texts would have still remained hidden if it wasn't for the collective scholarship of Coptic studies departments in Germany, Denmark, Switzerland and America, who send scholars each year to the Chester Beatty Library to decipher them." Recent discoveries in the Kellis oasis in Egypt of further Manichaean texts will add to the information contained in the Beatty holdings.

Collecting anything, whether stamps, works of art or Pok=€9mon cards, usually suggests an element of obsession, yet the remarkable Alfred Chester Beatty, mining millionaire and generous friend to Ireland, spent more than 60 years pursuing great art motivated by gentlemanly curiosity. His delight in ancient books and manuscripts led him to many rare, wonderful and even bizarre purchases -few as strange as the "sod of turf".

Dr Michael Ryan, director of the Chester Beatty Library, approached the Berlin Museum about the return of the Beatty material following an international conference in Berlin on Manichean texts. The conference reiterated not only the importance of the Dublin papyri but also the Chester Beatty library's ownership of the material. Berlin was keen to co-operate in returning it to Dublin.

More scholarly research was carried out in Germany during the intervening years as the Beatty collection was involved in a complicated move from Ballsbridge to Dublin Castle. Of the 125 pages that have returned, all individually sandwiched between sheets of glass, we examine two. The first is in good condition, the neat, black script in Greek letters is legible. The second is but a fragment. Ibscher once told Beatty that he had sneezed while working and lost an entire page.

We are standing in the research library, under the red Chinese ceiling Beatty shipped from his London home to Shrewsbury Road and which is now here in Dublin Castle's clock tower.The ancient pages are rolled in on a trolley. Their European odyssey has come to an end. Whoever wrote these plain, businesslike papyri pages lived at least 150 years before Christianity arrived in Ireland, long before the Book of Kells was begun and the high crosses carved. Beatty was right, his job-lot buy represents an early episode of civilisation's story.

The block - Ryan admits to being "too nervous to unwrap even with us all holding our breath" - will remain in storage until funds allow the unpicking of its final layers of text and the conservation, begun more than 70 years ago, to at last be completed.

The Chester Beatty Library at Dublin Castle is open 10 a.m.-5 p.m, Monday to Friday; Saturday: 11 a.m-5p.m.; Sunday: 1-5p.m. Website: www.cbl.ie