When you return to the Homestead, you'll talk to Achilles and then meet a friend of his. He is the son of a member of the Order though not a member himself. He will take you into New York to track down Thomas Hickey. When you get to New York, you'll follow him through town towards the markets where you'll find someone being called out for counterfeit money.
As the counterfeiter leaves the market, follow him. Like most tailing jobs, it's usually best if you can make your way to the rooftops. If you can do so slowly and still keep an eye on him then that's all the better. By rooftop, follow him as he makes his way through the streets. He'll eventually cross a main street that isn't easily crossed from the rooftops. Watch him as he crosses the street and then jump into the street behind him. As you approach the street he went down, you'll see a building just to the right. In front of this building will be a lift system and if you use this, it will lift you right to the roof so you can watch your target.
From here, you can watch him struggle with somebody on the street. After this, he will return to the main street, go up a couple of houses and then turn right again. Follow him up this new street and through a few backyards. Eventually, he will stop and you'll need to listen in on his conversation. This is tough because the guards in the area will take notice of you very quickly and there's not really any place to hide. The best place is if you go up to the platform attached to the red house on the right. There will be four large barrels that you can hide behind while you listen.
He will continue walking after his conversation and you have to follow after. He will cross back through the main street and into more yards. Some Red Coats will pass by him and he'll hop into a well to hide. Eventually, you'll follow him to another eavesdropping opportunity but this time you will have to follow him around town.
Drop to the ground and follow him through the streets. Watch on the right side for a group of people and blend with them when he stops. You'll watch him go around a corner to the left and then quickly to the right. Instead of following on the ground, use the boxes set up as steps on the right side of the alley to get just a little above him or the group of men on the left side of the alley for cover (though they don't always appear). Stay on the left side and take cover behind the wall that juts out. When the line catches up to you, make sure to walk along behind them.
You'll follow them straight to Thomas Hickey. After a brief confrontation, Hickey will take off running outside. Follow after him quickly. Follow him as her turns left own an alley but when he turns right in the alley, continue straight into the yards with the wooden fences. When you make it past a bunch of fences, you'll see a large wooden staircase to your right that is perpendicular to how you're running. IGNORE this set of stairs and you'll see another set of stairs directly in front of you that go up at an angle. Run to the left of those stairs.
This will lead you to a market area with most of the stalls set up ahead and to your left in a large outdoor structure. Don't bother going through the markets but instead turn left and follow this large road. You'll see a large hay cart in the middle of the road and then a small alley just to the right of that. If you've been going pretty fast, Hickey should be coming up that alley now. You can try to head him off and tackle him (B/O) but it's best if you let him go by you and follow right behind him. It's a lot easier to tackle him from behind because from the front he will attack you as you try to tackle him. Follow right behind him and as you close in on him, tackle him.
When you go to tackle him, be careful of people in the streets. You had a constraint that had you trying to avoid shoving people as you ran. While it's easy enough to do in a normal crowd, Hickey sometimes throws money behind him at intersections, causing groups of people to clump up. If you follow the path I gave you, you will have avoided all of them up until now. It's possible to catch him before he does this again but there's not a lot of space for you to do so. For this reason, be careful if you see him throw money or a crowd of people at a corner, stop running and "fast walk" through the crowd before continuing your pursuit.
