Combined Service Marines: Titanus Malleus

The CSM thought they had finally competed their operations on the Moon, but they were mistaken. They are finally on their way toward the moon Titan to rescue their comrades, when they received a distress call from the researchers still on the lunar surface. The transmission was short, but it was obvious that something had gone terribly wrong. A new enemy has risen from the ashes and it wants to eliminate humanity's presence from the Solar System.
Once the CSM answers the distress call, they make a startling discovery. The Moon has another secret.
There is an Artificial Intelligence deep within the Moon that has only one objective and that is to nuture the stock-race which had nearly been wiped out 65 million years ago by an asteroid that had slammed into the Earth. Unfortunately, humanity has no place within its primary objective. Man is considered to be a pestilence on the surface of the planet, where the stock-race once prospered. And there is only one solution, the Artificial Intelligence has determined that the human species has to been eliminated, so that the stock-race can be reintroduced onto the planet.
But humanity has another plan. Send in the Marines and deal with this alien intelligence their way.