"We call this Little Sister adoption," explained de la Plante. "He and the Little Sister are linked as a team in the environment."

"The Little Sister will point you to ADAM. She can gather it for you, but while she's gathering, you'll have to protect her," he continued. "She exposes angels to you. Angels are corpses that have ADAM in them."

At this point, the game will enter what the team called a "dynamic siege," where Splicers and, potentially, the Big Sister will attack the Little Sister while she tries to gather the ADAM.

"Mr. B, Mr. B--Big Sister doesn't want you playing with me," sang the sing-songy Little Sister on screen, as several Splicers began their assault. The player set several vortex traps around the Little Sister, then set them on fire with the Incinerator--a potent combination of plasmid powers that will now be possible in certain cases.

Soon the Big Sister appeared, however, and made short work of the scene--jumping down from the wall to land on the player and fade the screen to black.

Later on, I asked McClendon whether the Big Sister will largely be scripted, as seen in the demo, or if she will stalk the player through Rapture based on more subtle mechanics. His reply signaled a bit of both:

There are obviously are some scripted encounters with her because she's very important to the story, but we are as much as possible trying to make her feel like a living part of the ecology. The idea is that she's paying very close attention to how you behave, and she wants to keep the status quo in Rapture. When you come in and start disrupting that, by either harvesting Little Sisters or saving them, she eventually will take notice and come after you. We are definitely trying to have that feel very much like the bogeyman in levels, that she can come after you wherever you are. It's a reversal to your own relationship to the Big Daddies, where you can just follow the chump around for a while and wait to take them out. She'll be hunting you down.

McClendon also noted that environmental cues will warn the player when the Big Sister approacheth, allowing for some time to prepare for the impending siege.

"I'm really pleased and excited to see how [the Big Sister mechanic] turns out in the end," said lead level designer JP LeBreton, "because the Big Sister is a story character. So you're hearing in logs and trying to figure out how what her background is and stuff like that--but she's also a system character who shows up and fights you in response to what you do. That's just a really good stroke for game storytelling to me."

Fade to Black
With the world and mechanics sounding and looking quite polished, I was mainly left wanting for narrative detail. The promise of another spin through a fresh section of Rapture may be enough to sell a few million copies, but the rich subtext of the first game was something that would not be easy to replicate.

I asked the designers whether they would continue the careful layering of the first game's story, and how they would do so given the repeat of the setting.

"Rapture is definitely a place that crystallized out of Andrew Ryan's ethos, but even just Fontaine's purely self-interested, con-man type game--there are other ideologies in the mix, and that's going to be part of the world that you're seeing in BioShock 2," said McClendon.

Added de la Plante: "It's also interesting to see, with a mostly-different creative team, the things that we think are interesting. JP and I worked on the first one, but Zak didn't, and there are certain things in the world of Rapture that probably Zak finds really fascinating, that maybe people on the other team didn't really pay attention to."

Replied McClendon: "It's definitely something that is in sort of our core set of things that we absolutely know we have to do with BioShock, which is explore those kind of weighty issues and subtext. If we just sort of ride on the coattails of, 'Yeah, it's Objectivism again,' it's not going to be very interesting for a lot of people that have played BioShock."

And so I was left wanting for more detail, as is the case with most teaser events that see the majority of developer replies relegated to the words "not yet." As such, it's too early to judge BioShock 2 yet. Many elements of what made the first game special couldn't be gleaned from a preview build, and the same will likely hold true here.

But I didn't leave the room feeling disheartened by a lack of respect for the franchise, and I didn't get the sense that the team at 2K Marin wasn't capable of creating a story and a world that lived up to, or even surpassed, the original game. That may say more for the project than anything else at this stage.

BioShock 2 is set for release this fall on PC, Xbox 360 and PlayStation 3.