What is Richard Alpert, other than a kick-ass Maybelline pitchman?

Featured in this week's installment of TVGuide.com's Getting Lost video series:

• Ben describes his mysterious former colleague as "an advisor," and one who has held that job "for a very, very long time." But really, who or what is Richard Alpert? I share the two prevailing theories submitted by TVGuide.com readers — one of which just got some added juice from this week's episode

• Has Jack gone off the reservation with his plan to detonate a 40,000-lb. hydrogen bomb, all in the name of "saving" everyone? Executive producer Damon Lindelof teases a twist ahead for Jughead's new BFF.

• Speaking of Doc's master plan, this week's Burning Question concerns the two-hour May 13 season finale. Give my question a listen, then send your best guess to Getting_Lost@tvguide.com. (As you'll see, I even have filed my own prediction this time around!)

Next week: Executive producer Carlton Cuse gives us an update on, no, not the season finale, but Lost's May 2010 series finale.