Meet up with Donovan in his motel room to get new intel about Remy Duvall. But firs, you have to find a Southern Union Deacon. Drive to the marked location and the marker will turn to a large circle in the district. Drive around and keep an eye in your minimap. This time, the deacon will find you with a truckload of reinforcements. Unfortunately, this happens in public and if a police officer or patrol is within the vicinity, it will immediately trigger a police response. Don’t hesitate to call in reinforcements from Vito and disable the phones or use the police dispatcher Associates to get the police off of you. Attack the deacon and disable him. Once done, interrogate him and he’ll reveal the location of the Southern Union rally. Make your preparations and make your way to the mission marker.