The quest chain is not expounded upon in the official strategy guide.
The quest chain is not randomized; it is accessed via a very specific set of player actions.
The quest chain will not begin until you've completed a more well-known quest chain.
The quest chain requires that two weapons be upgraded to their maximum.
The quest chain features a sound puzzle. You won't even be aware of the puzzle's existence if your sound is muted. This may or may not be the reason why so few people have discovered the quest chain.
We intentionally left this quest chain out of the official strategy guide in order to encourage old school word of mouth "secrets".
This is why we've delayed the Creation Kit.
They've already announced the reason why they delayed the Creation Kit, and it wasn't this... and it sounds extremely unlikely... but :shrug:
Anyone found anything like this on X360 or PS3?