Warning: Spoilers ahead

I didn't love Bioshock Infinite, but I did really like the possibilities served up by its ending. 'There's always a lighthouse. There's always a man. There's always a city'. The end of the game made it impossible, for me at least, to do anything but imagine what was going on in all those other versions of Booker and Elizabeth's relationship.

It seems that neither could Irrational, and today saw the announcement of the Burial at Sea DLC for Infinite. If you've not seen the trailer, check it out.

While it might seem like a cheap way to score some cred with long term fans of the series - especially those that didn't like Infinite, or prefered either of the first two installments - the return to Rapture makes sense. The short jaunt there in Infinite was a reminder that Levine and co. hadn't bettered that world, and there were more stories to tell. A lot more.

The main one, of course, being the fall of Rapture. Bioshock 2's multiplayer mode aside, everything that we know of those events comes from second-hand sources, unreliable antagonists and warring propagandists. Seeing it through our own eyes would be something else entirely - actually being able to play through the series of events that leads to the destruction of one of gaming's most famous worlds sounds like a fantastic piece of fan service, as well as a great opportunity for the developer.

The trailer provides a short peek at what's going on, and what's there is suitably interesting: children being taught while wearing masks, citizens casually chatting, people perusing newspaper racks, society going on. It's this sort of detail that made the opening of Half-Life so memorable - seeing the world before its collapse informs your feeling about it after.

The counter argument to this is that witnessing what actually happens can never match up to what you imagined, especially after having all these years to put together a mental picture of what went down. Part of Rapture's appeal is that it is so alien. Those first few steps down into the lighthouse conjure up all manner of questions, not least about the design of the place. Knowing exactly what went down would be like getting all those questions answered in the Star Wars prequels, and we all know how that went down.

But then, which Rapture is this? It doesn't seem to be the one we fought through in 2007 and 2010. It could be, but given Elizabeth and Booker's presence it seems like a subtly different place. To some, the idea of there being an infinite variation on Bioshock's world cheapens and dilutes what has been created. There may have an element of truth to that, but it also enables Irrational to play around with Rapture, to see it from a different perspective.

Again, the trailer gives us brief insight into the changes that have been made. Elizabeth is now less scared young girl, more adult femme fatale. Her demeanour in the brief appearance she makes couldn't be more different from when you find her in the early stages of Infinite. Booker is running a detective agency in Rapture, with his would-be daughter hiring him for some sort of job.

It's set on New Years Eve 1958, the fall of Rapture mere hours away. What sort of enquiries Elizabeth is making is unknown, but I hope there's far more focus on actual detective work. The various political battles being fought could make for some interesting encounters and mechanics. I'd love to be able to play it as essentially a first-person point and click game: unravelling the mysteries of this Booker's life while digging deeper into the war that brings Rapture to its knees.

What I'd hate to see is another Bioshock title that over-relies on simply going around shooting dudes in the head, over and over again - Infinite's weakest element. Yes, essentially the games are about shooting, but it's still a valid complaint that the way it's handled left much to be desired, particularly the arena-based combat.

Should Burial at Sea be a commercial success - and it's hard to see how it won't be - we can hopefully look forward to more of this sort of DLC. One issue I took with the main game was that, despite the fact it could go anywhere with Elizabeth's powers, the route it took was rather mundane.

Going back to Rapture isn't the most radical departure either, but if it works out it could - and should - lead to different tales, told in different environments. Whether Irrational decide to do this or not - after all, they have the luxury of recycling old art assets here - is still to be decided. Either way, Burial at Sea could be an exciting addition to both Bioshock and Infinite's worlds.