The first ever of the New Adventures of Doctor Who published by Virgin between 1991 and 1997 (since I only recently read the first of the Missing Adventures). Actually rather good stuff as the Seventh Doctor and Ace find themselves in ancient Babylon battling an alien force, mixing it up with Gilgamesh. If I'd picked this up back in 1991 I would certainly have ended up buying many more. Biggest flaw - the silly title. Why the "y" in "Genesys"?
(Mind you, passing through Dublin airport last weekend, I noticed a new and horrible mutation of the Heavy Metal Umlaut - you can now buy your souvenir Irish fudge at a shop whose name is WRIGHTS ÖF HOWTH.)