On this page of our guide to BioShock Infinite you will find the second part of a detailed walkthrough of Chapter 5 - Monument Island Gateway. Use your Skyhook and sky-lines to travel across Columbia. Your main goal is a room where you can find the Prophet's Comstock's speech.
Leave the station to find yourself standing on a large platform with a barge docked to your right. Search the barge and then attach yourself to the sky-line to continue the mission.
Let go of the sky-line when you're under the archway of the maintenance tower. There's a room here and it's being guarded by two policemen. Explore the room to find Infusion #3 on the desk, as well as some money and alcohol.
Once you're done exploring the room mentioned above find Vantage Points #11- a telescope next to the balustrade. Get back to the sky-line to continue your journey to an upper level.
The sky-line at the top of the tower is blocked by gondolas. Deattach yourself from the sky-line (the best moment to do that is when you can land on a guard seen on a walkway) and search the rooms located on both sides. The room with the gondola control panel has a Voxophone #12 in the back. When you're ready activate the gondola and start following it using the sky-line.
The gondola will soon block your path again and this is the moment when you'll have to land on a nearby police barge. Your current destination is an abandoned apartment and you can get to it by using the Sky-Hook to reach its balcony. Before you to perform that jump deal with the police forces found on the square and search all containers.
Once you've made your way to the apartment you should look behind the dresser found next to the bed in the first room. There's some money here, as well as Gear #3 - Torso. The corridor leading to the terrace also contains a bottle of salt.
Proceed towards the terrace located on the other side of the apartment and start using the sky-line again in order to reach the next blockade.
Before you'll end your trip using the sky-line you'll notice that all policemen have received orders from Prophet and as a result they will enter a state of prayer, ignoring the main character instead of attacking him. Killing the policemen won't do you any good here, because they won't leave any loot behind and you won't be able to pick up their weapons.
Enter the building and stand on the service elevator while listening to Comstock's speech. Use the elevator to get to a new floor.