The Day of the Jackal (Penguin ELT Simplified Readers: Level 4:

The Jackal. A tall, blond Englishman with  opaque, gray eyes. A killer at the top of his  profession. A man unknown to any secret service in the  world. An assassin with a contract to kill the  world's most heavily guarded man.One  man with a rifle who can change the course of  history. One man whose mission is so secretive not  even his employers know his name. And as the  minutes count down to the final act of execution, it  seems that there is no power on earth that can stop  the Jackal.