A Scanner Darkly

The Nation is reporting that Mark Felt, a.k.a. Deep Throat,

was assigned the mission of unearthing--and stopping--Deep Throat.

This placed Felt, who as the FBI's associate director oversaw the bureau's Watergate probe, in an unusual position. He was essentially in charge of investigating himself.

And as long as I'm linking to Watergate articles: If you haven't seen it yet, you should take a look at the Albany Times Union's story alleging that at least three high-level FBI officials helped Felt leak information to the Post.