Not a fantastic title, but didn't want to put any kind of spoilers in the title.
The Librarian tells Chief that she 'planted seeds' that lead to his inclusion in the Spartan II project (so probably the project itself) as well as his Mjolnir armour and Cortana.
How is that possible? Or do we just dismiss it as forerunner magic?
I really liked the way Chief was meant to kill the Didact, I just wish I could understand it more!
-
The 'seeds' the Librarian mentions is referred to as a [i]geas[/i] - to put it in Layman's terms, a geas is a series of genetic commands imprinted in an organism or species to achieve a particular purpose. In CEA's Terminals, Guilty Spark confirms that humanity do indeed have a geas imposed on them which links to the librarian's "thousand lifetimes of planning". John is the culmination of that plan, and it seems that humanity are being nurtured by the Librarian to prepare for the return of the Precursors and the test they will soon put us through.