From Halopedia, the Halo wiki
Not much to tell, I'm a halo fan.
When Master Chief and The Arbiter watch the assault on the Dreadnaught only to have the Arc's gate activate.
Going through literal hell to only find out that Captain Keyes is dead. then punching through is skull in order to get a nav chip, the book describes it soo sickeningly.
But master chief is a pretty cool guy. eh shoots aliens and doesn't afraid of anything! :p