You have finally reached B5. This floor is easier as the Enigma building is running out of guards. However there are still traps and enemies waiting for you to come. You finally reach the machine at the end and have to destroy the main power generators and collect the crystals inside. But once you reach the end it seems the machine still hasn't shut down. In the distance you can see a portal. A portal into the internal mechanisms. That is where you must go next!