The laser beam that is fired in the chamber goes off every 90 seconds. You have that long to reach a chamber that will protect you from the laser beam. Every time you reach one of these doorways that protects you from the laser, it opens a checkpoint. First, if you are not already using Raphael switch to him now. You have a far jump to the first platform and, although you could use Mikey's helicopter move, it takes too long. To save time, do a team jump to this platform. You will see two red pipes with a narrow gap between them. Bird jump between them to the top of the next platform, then jump from platform to platform and step through the first doorway. As time grows short, the platforms will give way. You must be quick. Once the platforms give, the laser will fire and that is instant death. Also the doorway has a cage door on it closes while this is happening. You must reach the top platform and get into that door before the cage locks you out. Once the cage opens, jump the next platforms and you will get to a bird jump like the previous spot between the red pipes. You will now be on a platform that will have a power climb for Raphael to climb up. Climb the top and jump to the next platform that has the protection for you to make it to the next check point. You now have ledges that you must scale up along with the platforms to jump on. Rather than jumping to the next platform, run across the wall and land near or on the first ledge to climb. Jump up to that ledge to the longer one above it. Move to the end of that ledge and jump on to the swinging poles that are near it, then immediately swing across all three poles to reach another platform. Jump onto the ledges above it then scale across the wall and reach the final platform.