SOME NOVELS ARE spoiled by the author's doing too much research. Jane Stevenson's latest is spoiled by the characters' doing too much research. They are forever poring over obscure tomes in the British Library, or popping into the Bodleian ('the Bod') to check up on some obscure historico-scholarly reference. Although the reader may be just as much of a bibliophile as the author, this tendency in the characters hardly moves the plot forward with any great urgency, except in the hands of a master of the form such as Umberto Eco. Instead, The Empress of the Last Days (like A S Byatt's Possession, an evident progenitor) totters forwards like a determined but overburdened bluestocking carrying a hundredweight of venerable leather-bound books on her back.

This is a shame, because Stevenson's cool, erudite and seductive writing generally commands such admiration, not least the previous instalments of the historical trilogy that this new novel concludes, the brilliant Astraea and The Pretender. The Empress of the Last Days takes place in the present. And this time-shift reveals