Remark: you can begin this mission only after completing the mission 13a (Flight of Angels) or the mission 13b (Hunting the Hunters). Remark - game may won't let you begin this mission until you don't destroy the Mobile Command Centre in the Denny Park.
Marker of the new mission won't appear at once after finishing the previous one. You have to patiently wait for Reggie to call. Head for the northern-west part of the Denny Park and get onto the roof of one of the biggest building there. Listen to what Reggie has to say. You obtain new objectives.
Your new target is in the northern part of Uptown and you have to head there, listening to Betty on your way. When you get there, it turns out to be a crime scene. Approach the killed DUP soldier, take out camera and take a photo of the corpse. Be ready to get rid of enemy soldiers who'll suddenly appear nearby (it's good to return on roofs while fighting).
Stay nearby the crime scene and find a helmet, which you have to examine (press touchpad). Listening to the statement makes clear that it's Hank who have murdered this person (Hank gave Smoke power to Delsin at the beginning of the game). Prepare to defend against one more strong attack from DUP. This time you have to be more careful, because enemies will have various superpowers. There is also an armored carrier parked nearby (destroy it with R1 attack).
Continuance, you'll have to examine the crime scene. This time you have to find an area to which a narrow alley leads. There you can use the camera again. Make a photo of Hank's flies on the ground and listen to the new conversation. You get new objective.
You can head to the meeting place with, which is on the skyscraper's roof in the western part of the Uptown. When you get there, listen to the conversation and start flying to the southern-east, to the Downtown where Hank fights DUP soldiers. Get to the roof of the building in the northern-east corner of the mentioned district and eliminate DUP soldiers. You don't have to destroy helicopters flying over the building but try to get rid of normal soldiers rather quickly to not get hit by their rockets.
As I said, you don't have to take down helicopters, so when you only see a marker, head for the Rainier. Try to get close to the Hank, who'll start running. During this chase, you have to try very hard to not get far away from this man. Be careful especially where Hank uses shafts, quickly getting on the roofs. When it comes to choice of power, you don't have to rely only on Smoke, cause you can move quickly also with the Light Speed (Neon) and Video Surge (Video). Chase lasts several dozens of seconds. Its end is also a final of this mission. Another main quest on your list is Quid pro Quo.