I can't open the door!

Hint 1 of 15:

Try pulling really hard on the handle.

Hint 2 of 15:

No matter how hard you pull, you can't open it.

Hint 3 of 15:

You need outside help.

Hint 4 of 15:

Like a machine, for instance.

Hint 5 of 15:

Have you found the elevator in the strange building yet?  If not, see the
topic on the strange building.

Hint 6 of 15:

The elevator is a machine.