This is the direct sequel to Commander Keen: The Earth Explodes - it's the third and final Commander Keen adventure in his first trilogy titled Invasion of the Vorticons. In the last episode Commander Keen destroyed all the Tantalus Rays and disabled the Vorticon Mothership and watched as it limped home, back to where it came from - the planet Vorticon VI. Keen lands next to the city of Vortiville and continues on through various forts and cities, passing the incredible maze of the Caves of Oblivion. Eventually Keen will reach the Castle of the Grand Intellect. Just who is The Grand Intellect and can you stop him before he destroys Earth? The Vorticon Elder from episode 2 told you two things: the Vorticons are not evil - the Grand Intellect is controlling them with his "Mind-Belts". And the Grand Intellect is from Earth! Who could he be?
