No Hollywood scriptwriter would have dared pen such an outrageously unlikely plot. A boy of immigrant parents raised on a south London council estate, who couldn't speak, read or write for most of his childhood, overcomes such astonishing odds to become, at 37, the youngest black professor at the University of Cambridge. Ever since, life's glittering prizes in the shape of honorary degrees and academic accolades have cascaded down on Jason Arday along with lavish and high-minded praise. Yet this week, a fellow don has pulled the rug from under those achievements in an excoriating assassination of Arday's work and...