My emergency brake does not work.

It's very important to note that this "emergency brake" is merely to secure the vehicle when parked, not really designed to act as a method of stopping the vehicle in general. Sure, as a cable operated system, if your hydraulic brakes are compromised, this system can help slow your vehicle down. But it sounds like it may already be operating as designed. The parking brake when engaged pulls on cables that pull on actuating mechanisms on the rear brake calipers to hold the vehicle in place when stopped. This is the primary purpose of that hand operated brake. I do not suspect the brake pads are at issue here, because the same brake pads stop the car with normal brake operation.