Imagine this: after a nine-day camel ride from Suez in 1892, identical twin sisters from Scotland arrive at the Greek Orthodox Saint Catherine’s Monastery at Mount Sinai. They find a decrepit manuscript of the Gospels, unread for at least a millennium, written in an obscure language that one of the twins had started learning only a few months previously. The manuscript astounds biblical scholars and fascinates the Bible-reading public.

It’s a preposterous story. And it’s true. Janet Soskice, professor of philosophical theology at the University of Cambridge and a fellow of Jesus College, has written a lively and lucid biography of these intrepid sisters, Agnes Smith Lewis and Margaret Dun lop Gibson (1843–1926 and 1843–1920, respectively). Don’t let the title be a turnoff. The phrase “lady adventurers” might be grating, and some of us may feel we’re going to scream if we see one more book purporting to reveal hitherto unknown secrets from “hidden Gos pels,” but not to worry. The subjects’ gender is a significant part of the story, and what they found was a manuscript of the four canonical Gospels.

A good biography can be as much fun to read as a novel, and in this case an added benefit is that the reader learns a few things about the Sinai Peninsula, Cambridge University, travel on the Nile, camel camping and textual criticism.

The twins’ story is, among other things, a story of overcoming the disadvantages of being an outsider. Though we might not see wealthy European women as victims of marginalization, the twins were working in an academic setting without the credential of a university degree, and they were women working in a male environment. More over, they were not landed gentry, they were Scots in England, and they were Presbyterian where one was supposed to be Anglican. (Until 1871, anyone holding a university post at Cambridge was required to be a member of the Church of England.)

Lewis and Gibson felt an imperative to do something significant with their lives, and with a large inheritance and no family responsibilities, they had the means and leisure to do so. In The Sisters of Sinai we read about their discernment of their calling, which they undertook in middle age and without a midlife crisis.

The book can also be read as a story of their faith, although Soskice does not play up this aspect of their lives. She does make numerous references to the twins’ belief in divine providence, but she does not do much to link their Christian faith to their motivation for scholarly achievement. Soskice also touches on the tension between religion and science. The twins lived at a time when archaeological discoveries and textual criticism were sparking a reassessment of how to understand the Bible.

The twins’ upbringing and a re markable childhood pastor fostered their zeal for travel and their interest in learning foreign languages, which in turn provided the foundation for their scholarly careers. Lewis and Gibson each had one happy, late-in-life marriage lasting about three years and ending with the death of the husband. The marriages did not overlap, and in both cases the twin who was single at the time lived with the couple. The twins picked up professional skills from their husbands, and those skills came in handy later.

Much of the book is devoted to the sisters’ first trip to Mount Sinai to look for ancient biblical manuscripts, particularly those written in Syriac, a dialect of the Aramaic spoken by Jesus. Their big find, in a closet in a desert monastery, was the earliest known Syriac version of the four Gospels—in the form of difficult-to-read underwriting in a palimp sest manuscript, the pages having been scraped and the text written over. The twins struggled to get the appropriate experts at Cambridge to look at their photographs, then traveled back to Sinai with scholars who could help transcribe the text. They wrangled with the various experts about getting the text published and about who deserved credit for what.

A few years after finding the Syriac Gospels, Lewis and Gibson bought some manuscript pages in Hebrew that turned out to be part of the book of Ecclesi asticus (Wisdom of Ben Sira). This was exciting because until then Ecclesiasticus had been known only in translation, and some doubted that there had ever been an original in Hebrew.

Soskice shapes her narrative by contrasting the world of professional scholars holding degrees with that of the amateur sisters who had only do-it-yourself credentials. At that time Cambridge University did not grant degrees to women, and women were sometimes not even allowed to sit in on classes. The twins went to finishing school in London in the early 1860s, and they received a number of honorary doctoral degrees from major European universities starting in 1899. But they received no earned degrees in between. Soskice interweaves the various facets of their lives—their personal circumstances, travels, charitable and denominational projects, and extensive roster of publications—showing how all the pieces came together. She also provides background information on some of the sisters’ interesting friends, including William Robert son Smith, J. Rendel Harris and Solomon Schechter.

One can hope that this book will rescue Lewis and Gibson from undeserved obscurity. Syriac used to be more widely studied than it is today, and the twins’ achievements, difficult to appreciate fully even in their own time, have largely been forgotten. A previous biography, The Ladies of Castlebrae, by A. Whigham Price, is an affectionate tale of travel and adventure, but Price did not aim for the level of research and scholarship that Soskice applied to The Sisters of Sinai. This book may act like the chemical reagent Lewis used on the underwriting of the Syriac manuscript to bring the obscured story to light.

Lewis and Gibson demonstrated faith that was tenacious enough for them to spend a long time discerning a vocation and to engage with different faith traditions and with religious skeptics. Soskice refers to their “‘fearless Presby terianism,’ which, because it was confident of the basics, was prepared to consider all the opposition cool-headedly.” One doesn’t need to be Presby terian to emulate their example of combining critical thinking with a faithful life.