Originally posted by StarWarsFanMan


Sorry to say this but most of those answers are way off .

1. The Forerunner (a mysterious, powerful alien race that disappeared) built Halo to study the Flood, which they apparently created. The Flood is a parasitic species with a simple reproduction procedure. The spores (little octopus things that swarm you in large numbers) attach themselves to a host (dead Marine, dead Elite, any other suitable creature that is dead) and embed themselves into the chest cavity and take control of the body and mutate it into a Flood worker/warrior or carrier. The worker/warriors are the guys that have tentacles grown on their arms and can jump really far. The carrier Flood (I like to call them nutsacks ) walk to a host and detonate to realease the spores to infect the host. That explains the Flood. (You can read into more detail here: The Flood

2. The "robot things" are Sentinels. They were put on Halo by the Forerunner to contain the spore Flood to prevent an outbreak on Halo. Their beam weapon works extremely well on the spores, but not the worker/warriors. The "blue eye" is 343 Guilty Spark, the AI left on Halo by the Forerunner to monitor Halo and repair/maintain it when necessary. He helps you in the Library because he wants you to reach the Index, to activate Halo (the sinister part of his plan). When he takes the Index to the control room, he discovers Cortana in the core. Cortana reveals 343 Guilty Sparks plan to activate Halo and wipe out all sentient life in the galaxy by activating Halo to Master Chief, who asks 343 Guilty Spark if that is the truth. Guilty Spark says it is and from then on, tries to keep you from destroying Halo (along with doing its best to activate it before you destroy it).

3. Halo is indeed a super weapon that can wipe out anything within 25,000 light years (a light year is the distance light travels in a year). 343 Guilty Spark is trying to activate it and that's why you are trying to destroy it.

4. Your ship, The Pillar of Autumn just escaped a battle to a "random" spot in space. The Covenant followed you because they knew that Halo was a weapon that was very powerful and they don't want you (the humans) to take control of it and use it against them. That is why, when you land on Halo, the Covenant tries to stop you from reaching the control room to activate Halo.

That is as best as I can explain it!
Some of your answers are WAY off too. For one, Cortana took the ship to a NAV point she found in space off a rock that was found on Sigma Octanus IV. It wasn't RANDOM at all. If you want more answers then read Halo: The Fall of Reach.