London: Printed for G.G. and J. Robinson, 1794. Near fine.. First edition of the Ur-Gothic, the literary sensation credited by many for inaugurating one of the first major trends of the English novel — and the literary heart of Austen's NORTHANGER ABBEY, which is both a satire of and homage to it. THE MYSTERIES OF UDOLPHO is a gothic thriller that follows the heroine Emily's tortuous path to womanhood, from a picturesque journey through the south of France, to scandalous parties along Venetian canals, to her extended imprisonment at ominous Castle Udolpho. Radcliffe sold the manuscript for £500 — more than double the previous record paid to an English woman. When the publisher Cadell heard the amount, he was so sure it was an exaggeration that he wagered ten pounds against it. (He not only lost that bet, but then went on to pay even more himself for the rights to her next novel a few years later.) The book was an immediate hit: readers reported staying up all night to finish…