The Vampire Diaries: Does the fourth coffin hold the key?

Jan 12, 2012 at 10:10 p.m. ET

The big, bad Klaus huffs and puffs his way through Mystic Falls -- Happy birthday, Caroline!

The Vampire Diaries better do us a spell and open that fourth coffin soon or someone's going to end up in a straight jacket -- and we don't mean the characters!

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In "Our Town," we saw Tyler stand his ground, Stefan threaten Klaus and Caroline blow out her b-day candles -- but we also realized that this thing with Klaus is far from over -- and it's all about that dusty fourth coffin.

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We've been putting the pieces of the coffin puzzle together, and thanks to "Our Town," and Damon's need to point out the obvious, we know the fourth coffin doesn't hold an Original sibling -- it can't -- there's three siblings and four coffins.

Here's our theory: This coffin business is sending everyone into a tailspin for very different reasons, but Klaus more than anyone for obvious reasons.

What if the mystery person in the coffin isn't just the key to controlling Klaus, but the key to everything these characters have been struggling to understand?  

Either way, whoever is in that coffin, it brought out a "pissing contest" between Klaus and Stefan that left Caroline with a hybrid bite courtesy of Tyler and Elena at the hands of her former hero and love.

Stefan sped his car toward a bridge with Elena as his hostage, threatening to kill her if Klaus didn't send his hybrids away -- yes, she had a belly full of Stefan's blood in her. Yeah, Klaus kind of needs her alive.

Stefan one, Klaus zero -- for now.

Klaus then paid his collateral damage, Caroline, a visit with a promise of 1,000 more birthdays, offering his wrist as her birthday gift. Woo hoo! Happy birthday, girl! You've been saved by a lunatic.

We have to give a special shout out to Jeremy this week, who we never thought would actually go to Denver, but said a sad goodbye. Is this for real?

We're going to go out on a supernatural limb and leave you with this thought: Could the original doppelganger be slumbering in the depths of that fourth coffin?

Bite on that!

Who do you think is in the coffin?

Photo credit: Bob Mahoney/The CW