Fallout 3: Broken Steel

What ensues is a sizeable trek in search of the necessary components - a radioactive riff on Supermarket Sweep that plays out in a now familiar mix of puzzles and combat scenarios. You'll travel across the map from Olney to Adams Air Force Base, an entirely new DC location. There things must either get really exciting or simply conclude, as that's all Bethesda's revealing at the moment.

To get to the base, you'll first need to navigate the forgotten Presidential Metro system running under the nuked remains of the White House. It was the venue for a pitched battle between sentry bots and armies of ghouls when I dropped in to visit. Watched over by a mysterious computer system named Margot, a ride through such shadowy confines is a tempting notion, and another claustrophobia-inducing chunk of intrigue from a game that uses its world famous setting to endlessly good effect.

Bethesda's also thrown in the requisite toys. New enemies include a fresh breed of super mutant named The Overlord, and the heavily-armoured Feral Ghoul Reaver who, from what's been shown so far, is a bit handy with grenades.

New weapons start with the Tesla Cannon itself, which fires extremely powerful blasts of electricity. Its ballistic strength is balanced with a relatively long reload - a fact you can forgive as it appears to be capable of knocking aircraft out of the sky in a single shot.

Tesla's not the only new gadget; The Overlord has his own make of laser and there's a new flame weapon of some kind. It seems to work like a kind of mortar, lobbing fire over its target in lazy arcs. On top of that there's a range of new perks, the only one revealed so far being Puppies, which allows you to collect a fresh (and identical) relative of Dogmeat whenever you're careless enough to let him get killed.

You can also expect more Achievements, new armour, and, most excitingly for Matthew Perry, if the recent news stories are to be believed, the upping of the level cap from 20 to 30..

Bethesda's promising it will be a struggle to work your way up those last ten levels. While the main quest of Broken Steel will most likely weigh in at around four or five hours, rendering it the longest piece of extra content yet, levelling and completing the various side-quests are designed to make it well worth the 800 Microsoft Points (GBP 6.80 / EUR 9.60) it will cost.

There's no reason not to believe that will happen: from even the most cursory of developer-led guided tours, this latest DLC already feels more substantial and relevant than either The Pitt or Operation: Anchorage. It's not quite as elaborate an expansion as Oblivion's Shivering Isles, but in many ways it's something more important. By rectifying the problems many people had with Fallout 3's original ending, Broken Steel won't just expand on the game's world - it will reopen the doors for those who never got to see everything the first time around.