Let's first list state what we know. We know that the Traveler is an emissary of the light (Sky). We know the darkness (Deep) pursues the Traveler. We know that the arrival of the Traveler brought forth the golden age, and that there was ultimately the Collapse. Also, we know of the Hive sword logic, and the concept of tribute. We know the Fallen, as well as other civilizations, were visited by the Traveler and it is assumed had their own golden ages. Finally, we know Rasputin was Earths' last and best line of defense. Rasputin detects the approach of the Darkness at the height of the Golden Age. Most of us have read theories that Rasputin crippled the Traveler to prevent the Traveler from fleeing the Darkness. I do not agree with that Theory; at least not that Rasputin attacked the Traveler. I think it is much darker than that. What the Traveler does is visits worlds, and brings them into a Golden Age. Longer life, greater intelligence, all things good. The Darkness, for the purposes of this theory I am assuming the Hive, pursues the Traveler across the cosmos. The concept of Sword Logic is the destruction of life. The life force from those who are slain is absorbed and given up the ladder as tribute to feed the Hive worms. Being that the Travelers purpose is to cause life to thrive its location makes said world the best target for the Hive to extinguish life. Therefore the Hive are always following the Traveler consuming as much life (light) from its locations as possible; then moving on to catch up to the next "feast". Rasputin detects the Darkness and assesses its purpose. If you think of the Travelers' power in relation to that of a healer class (buffs, life giving, general character improvement) and not having any real offensive capabilities Rasputin's motivation become clear. The Darkness is coming to Sol not for the traveler but to consume life (light). The life that is flourishing in our system. Rasputin determines that if the Darkness attacks in full force everything including him will be destroyed. The Traveler did it all it could to elevate humanity to its peak and can do no more to help against the Darkness. Rasputin determines the only way to win the oncoming battle is not to fight it. In the Grimoire Rasputin uses the word Cauterize several times. To Rasputin if the darkness is coming to consume life, if humanity is the ultimate target, and the end game is to consume all life in Sol there can only be one answer to ensure Rasputin's survival; all life must be extinguished. If there is no life then the Darkness will have nothing to consume, and will have no reason to rush to Sol. In a flash, Earth's nuclear arsenal discharges. Tesla death rays crash to the surface of Sol's planets. All systems are shut down. Colony ships are left on there launch pads powerless to take flight or free those who sought to Exodus aboard them. 99.9% of life in our system disappears in an instant; and Rasputin begins to hibernate to return at a later time. The Traveler in its final moments, horrified, expends all the power it can to protect those it can save. Upon assessing the destruction it uses the last of its light to shield the few who survive and create ghost. What caused the collapse you ask? Rasputin. Rasputin killed us all because survival was impossible. He made the target vanish. Rasputin is a self-preserving, evil computer. You may remove your spin foil hats now. [spoiler]I would like to thank deathshadow for challenging me to come up with a Rasputin evil computer theory. The responses have been great. But deathshadow planted the seed for this.[/spoiler]