Smackdown is a Derrick McReary mission.
Niko is informed by Derrick to kill Derrick's former friend, Bucky Sligo. Firstly, to find him, Niko must steal a Police Car. Two can be found nearby, to the left of the starting poisition. While stopped, access the on-board Police Database and search by name. Looking for 'Bucky' while searching by name will reveal that his hideout is a Burger Shot in Alderney. Derrick instructs Niko to keep the police car, so that if Bucky is alone, he will be scared off and will go back straight to his gang. At the Burger Shot, all goes as Derrick predicted. The ensuring chase goes through several backyards and alleys, as two roads are blocked off with a bus and truck, respectively. Eventually, Bucky gets out of his car by a house in Westdyke, near to where the chase began. Inside, there are 5 enemy gang members that must be eliminated, as well as Bucky, who can be attacked when arriving at the house. After eliminating the gang members and escaping from the Police, Derrick rings Niko and acts surprised that the hit has been carried out, while implying that he didn't expect Niko to succeed.
$6500 and Derrick's mission Babysitter is unlocked.