Once the mission is triggered, El Burro tells the protagonist that he has a job for them, and says to head to Central Eagleside and answer the phone there. Once there, the protagonist is told that someone is using buses to bring people across the border illegally. Burro is unhappy about this as it is eating into his profits. The protagonist is ordered to collect a Rocket Launcher which El Burro had left in an alley in Woodside. The protagonist must use the Rocket Launcher to take the buses out of service.
Five of the buses are located in a car park in South Aye Valley. Once they have been taken care of, El Burro will tell the protagonist that there are still two more buses out and about. These buses are found traveling along the highway. Once all seven buses have been destroyed, the mission is complete. Part 2 of Phone 17 will automatically commence shortly after.