XIII 18 - The Last Round var det siste albumet fra seriens opphavsmenn og dermed slutten på den første syklusen. Her starter en ny, med ny forfatter og tegner, dog nøye kontrollert av  Jean Van Hamme.
 
"He was XIII’s most dogged enemy from the start, but who really was the Mongoose, that mysterious assassin-for-hire who nearly killed the amnesiac hero so many times? During an encounter between him and Kim Rowland - an event that took place just before the start of the XIII series - the merciless hitman tells the story of his childhood and how he became a contract killer. ‘Anyone would have in my circumstances’, he claims. But would they? You be the judge."