Instructions
Head inside Fort Francis, and travel until you come to Carrie, a caged Pixl.
Use ground pound to free Carrie.
Tell her that Francis is a geeky geek, and she'll join you.
Continue until you reach a large, cat-shaped locked door.
Go through the next door, and change over to 3D mode to jump up a series of platforms.
Go through the door at the top. Midway through the room, you'll find a door hovering in the air.
Use Thudley's ground pound to bring the hovering door down, and go through it.
Use Carrie to cross the floor where it's covered with spikes. When you reach the far side of the room, go through the door.
Find the security cat for a locked room.
Answer "True" to all three of its questions, and type the passcode "2323."
Enter the elevator that appears.
Ride the elevator all the way to the next room, where you'll find a cat maidbot.
Jump on top of the maidbot, and jump again into the upper-left corner to find a chest containing the first key.
Backtrack to the hall where you found the hanging door. On the left, you'll see another hanging door.
Use ground pound to knock it down, and go through it.
Jump up onto the ledge, and use Peach to float across the room to the next ledge.
Continue climbing until you reach a door.
Grab onto a flying cat using Thoreau, and throw it at the blue switch.
Cross the blue bridge that forms to reach a door on the far side. Here, you'll find the second security cat.
Answer "True" to all of these questions, just like the previous cat, and type "2828."
Jump on top of the maidbot to reach a high platform, just like with the first key, and you'll reach the chest with the second key.