Story:
The Boss of Sindacco Mafia; Don who usually lives in Las Venturas came for a contract with the Rifa at San Fierro. The Mafia wants to trade drugs as they're selling high like their counterfit chips and also the Rifa has the most skillful men for delivering them. Don decided to create an alliance with the Rifa. Diaz expected it that trading counterfit chips and support of Mafia makes him even richer. He sent Casey to pick him up for escort as they're the old rivals of the Triads. As Casey went to see Don, the Triads ambushed them right away. Casey, Don and his men successfully wiped the ambush crew but more are blocking their way. Don made Casey incharge temporarily for escorting Don to Diaz. Don, his men and Casey successfully made it to Diaz and the deal continued.
Note:
It's forgot to mention the Elite Cup objectives. Here are they:
Swift Escort - Complete the escort within 4 minutes.
Body Count - Kill 30 Enemies.
Headshots - Getaway 15 Headshots.