Where is the red card?

Hint 1 of 5:

The red card will open the door at the top of the steps in the sewage area.

Hint 2 of 5:

This is the sewage area you will get to after you escape from that corridor.

Hint 3 of 5:

In any case, look for the spinning cogs.

Hint 4 of 5:

Get between the teeth, and wait for an opening.

Hint 5 of 5:

Jump in that opening.