"LOST" Among the Tombstones

SPOILER ALERT! "LOST" returned to Oahu Cemetery this morning, perhaps a fitting location on the brink of Halloween. The historic graveyard previously appeared in the Season 2 episode "Lockdown," as the not-quite-final resting place of Anthony Cooper.

It seemed, at first, a peaceful scene, with Matthew Abbadon (Lance Reddick) bringing a wheelchair-bound John Locke (Terry O'Quinn) to a modest gravesite for an intense conversation.

But things turned quickly when it came time to leave. Locke, in the back seat of a blue four-door sedan (I'd guess it was a late model Mercury Grand Marquis), waited as Abbadon loaded his wheelchair into the trunk. But no sooner had Abbadon closed the lid, when shots rang out. And Abbadon is hit.

Who's gunning for Abbadon? And whose grave were they visiting?