Cat & Mouse by James Patterson

Alex Cross is back, and so is a raging and suicidal Gary Soneji.

Out of prison and dying from the AIDS virus he contracted there, Soneji wants revenge on Cross before he dies.

There's more. We are introduced to a new pair of rivals whose paths cross those of Cross and Soneji. Thomas Augustine Pierce has been chasing his demon, Mr. Smith, since the savage murder of his fiancée. Smith is a unique monster, with interactions between him and his victims so insane, so unimaginable, that he is thought of as "not of the earth." Pierce, known in the business as St. Augustine because of his track record for catching killers and his invaluable status to the FBI and Interpol, may even be better than Cross. When things heat up and Alex is in a near-death coma following a strange attack, Pierce goes to Washington to help investigate. But then he is summoned to Paris with a postcard from Smith inviting him to a very special killing.

The body count is high, the tension the highest, and the two killers on the loose are watching every move their pursuers make. Who is the cat, and who is the mouse? What and where is the final trap? And who survives?