Lego Batman Strategy Guide 104: The Lure of the Night, Free Play, Part 2
When you clear the one area with the explosive, you will find a pile of boxes that require a super strong to move. Go ahead and move those, but you will have a hard time as some of them are stack atop others. You will then assemble a spinner, and use it to operate a mechanism that will create an inflatable raft. Go ahead and get in the raft and go around, following the direction of the arrow. The seemed to do the trick ,and the Seventh Canister appeared to me.
Go ahead and use the Joker’s power on a shock generator and create an elevator. Go across the bridges and into the next area.
When you get to the area where you need to build the helicopter, there is a vent on the outside of a building. You should be able to use some explosive down below it, and you can build up the vent to be a complete magnetic wall. Use Magnet Suit Robin to climb up and over, and you will be on a fire escape with the Eighth Canister.
When you get to the park, you will need to suck up as much Attracto Debris as possible. From there, you should go to the machine in the park, and it will make two pots. Poison Ivy can use her powers on these pots to create some plants that she can jump on to get the Power Brick.
To get out of the park, here is a review of how to leave. In the trees is something that you must push off. It will fall, and you can rebuild it into a spinner. Since there is toxic waste in the proximity, become a toxic-resistant character and rebuild the spinner. It will open the gate to the next area.
In the next area after the park, there is a door that is shiny and locked off. Just send one explosive to detonate it, and it will open. You can then grab the Ninth Canister.
The last canister is shortly after you get the giant jack in the box robot. There is one area that is cordoned off by fence, but it is easy to blast through. There is a big fish tank area, and you need to climb the ladder and jump into it. From there, go ahead and sink to the bottom, and hit one of the buttons. The water will drain out almost all the way to the floor, and you will see the Canister behind a shiny area. Just use Sonic Suit Batman and break the glass. Claim the Tenth Canister.