ACT 2 - Mission 01: Hold On, Kiddo
Objective: Reach Nicky's house
Looks like things are going bad at Nicky's house and Aiden needs to get there fast. Sprint for the street and grab a car. Burn rubber to Nicky's place and head inside for a cut-scene.
Objective: Get to the train station where Jackson is located
After the cut-scene ends, Aiden will realize that Jackson is in trouble and locate him. After the marker appears, get back in a car and head for the station on the map. On the way, Clara will give you a one time hack, that allows you to control a train (this ability can also be gained in the skills menu, but for this mission you need the specific once off hack). As you approach the station, the fixers will already be preparing to ambush Jackson.
Objective: Hack the train undetected to get Jackson away safely
Get out of the car and immediately hack the train to get Jackson out of there.
Objective: Take down the fixers before they reach Jackson & Eliminate the remaining fixers
Time for some old fashioned high tech vigilante justice (wait, what?). Roar off in pursuit of the fixers in your car and use the neutralize prompts to bring them down (much safer than a firefight). You should have plenty of time to get rid of both cars. If all else fails, ram them off the road and then run them over when they exit the car. If you have grenades, they make quite an impact and a good for clearing goons that are near a car.
Objective: Board the l-train and find Jackson
Once the fixers are no more, head for the nearby train and hop on to reuinite with Jackson and watch a cut-scene after which the mission ends.