As loyal Lost viewers know, not much scares Locke. Or Fake Locke. Or The Man in Black. Or whatever name you use to refer to Terry O'Quinn's season six character.

But a young boy has randomly popped up twice on the island so far, causing major panic in the eyes of Fake Locke: once in "Recon," as the latter roamed the jungle with Sawyer; and once last week, as he did the same with Desmond.

Therefore, the obvious question remains: Who the heck is this child?!? A few theories:

• AARON: From season one, he's been considered a key to the island. And he's a boy.
• JACOB: Who else would put such fear into The Man in Black?
• DESMOND: He's special, right? Magically appearing in the jungle as a younger version of himself would definitely qualify as "special."
• WIDMORE: He has a claim to the island. He thinks he's its rightful leader. But why would an elder Widmore be trying so desperately to return and save it, if his younger self is already an important presence there? My head hurts.

Who do you think this child is? As you ponder that question, get excited for tonight's episode via its official ABC promo and a few photos from "The Last Recruit."

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.