The theme of choice is one that resonates deeply through BioShock Infinite. Some of the game's best moments were ones that highlighted how choices, even ones that seem small at the moment of decision, can ripple back and change events drastically when seen in the rearview. This theme translates smoothly from the floating city of Columbia to the sunken metropolis of Rapture, although it's one of the precious few constants between the two BioShock stories.

Infinite's first story-focused DLC, Burial at Sea brings players back to Rapture, but as the protagnists of this year's BioShock Infinite. Booker DeWitt makes his living as a private detective in the city, and he's about to have the wildest job of his career as the events of the first BioShock are about to kick off outside his office. Things don't get too crazy until Elizabeth comes in to the picture as his client, though.

Keep in mind that these characters aren't the same as they were in BioShock Infinite, and the version of Elizabeth that you see here is a bit more grown-up than the naive girl she's presented as in Infinite's core game. Other things have changed in the transition, too. Instead of fighting Big Daddies, you'll begin the game observing them as they dutifully patrol Rapture and keep order. Instead of drinking Vigors, you're back to injecting Plasmids, although they have largely the same effects.

Perhaps most interesting is the way that Burial at Sea mirrors the opening act of Infinite. You'll spend the beginning of this DLC roaming around Rapture, observing life unfold around you, exploring, eavesdropping on cnoversations, and discovering new Audio Logs. Like Infinite's better moments, this opening act allows you to soak (har) in the culture of a world that is vastly different from ours. And even though this world is a little more familiar than Columbia by now, it's an opportunity that is greatly appreciated and that pays off nicely when the chaos finally begins.

Once Rapture starts to crumble, Booker and Elizabeth are off adventuring together once more, this time in search of a missing girl. The story starts off strong, but be warned - you won't appreciate things nearly as much if you haven't finished the core game. The very conceit of this DLC makes little sense as anything more than fanfiction if you don't have to context of Infinite's ending to wrap up the lore.

Being a two-parter, Burial at Sea leaves lots of questions to be answered in the second chapter (which will have you playing as Elizabeth.) What we can say thus far is that the story kicks off to a thrilling start, and we can't wait to see where Irrational takes things from here. Rapture is one of the most engrossing gaming worlds ever created, even six years after the release of the first BioShock game, and the team at Irrational does it - and its potential for great storytelling - justice thus far.

That's not to say everything's perfect in Rapture, though. Series fans have explored the sunken city twice by now, and while the opportunity to revisit is welcome, it doesn't necessarily induce the same thrills as poking around Columbia for the first time did. One of the best parts about Infinite's core game was the sensation of discovering a new and believable fantasy world for the first time. That sensation is absent here.

A few minor tweaks to the gameplay ensure that Burial at Sea's combat is up to the same standards as Infinite's, although there are a few elements that feel a bit out of place in the underwater city. Specifiaclly, the Sky Rails return, although they conceptually feel far more at home in the open skies of Columbia. The Weapon Wheel from the first two BioShock games also makes a return, allowing you to carry more than two weapons at once. This is a great feature that remedies the one complaint I had with Infinite's core game. On the other hand, you can't hold much ammo for any one gun at all, meaning you'll have to be playing a constant swapping game to stay on top of the action. I personally preferred this tension to the plentiful ammo of Columbia, but it's more of a personal taste thing.

The most unfortunate thing about Burial at Sea is its use of new items. While the blending of new and old combat mechancis makes things feel fresh and fun, the new weapons you'll get feel crammed in and only open themselves up to you in the last 15 or so minutes of the DLC. A new radar beam turns your enemies into living explosives, but you'll barely have any time to play around with it. Additionally, the "new" Old Man Winter Plasmid is basically the same as the old Winter Blast Plasmid.

Presumably there will be more time to play around with these new toys in the second chapter of Burial at Sea, but as is the addition of new weapons and Plasmids feels like an afterthought. The story and atmosphere that propel the DLC, however, do not - BioShock Infinite remains as compelling as ever, and while it remains to be seen if Burial at Sea's plot can hit the dazzling heights of the core game's, I'm optimistic for at least a solid resolution in Part 2. At $15, Burial at Sea is a bit expensive if you consider yourself a casual fan of BioShock, especially taking into consideration what you get out of it. But for hardcore fans of the series, this return to Raputure is practically a must-play.

Score: 8.5/10