Time was frozen, Alyx was in danger, there was a blinding light and the G-Man whisked us away before disappearing. The colours faded into darkness and we were left alone. But not, it seems, for very long.
We begin where we left off: there's a Citadel crumbling around us, a city lying in ruins around it and a damsel that needs relieving from an element of distress. Even though we'd never say that to her face. There aren't too many damsels that pack as much firepower as Ms Vance - and this time round, Valve is promising that she'll have even more kick to her... But let's get down to it: what do we know about this episode, once an expansion? What bedazzling nuggets of previously unheard wonderment did we extract from Valve designer Robin Walker in our cosy tête-à-tête?
As you may know, Episode One plans to peremptorily remove Freeman from stasis apparently way before schedule - starting the very instant that Half-Life 2 ended. From here runs four to six hours of densely packed Half-Life wonderment - in typical fashion raising as many questions as it provides answers for, but addressing, in the words of Walker: "What exactly happened to the Citadel after that big explosion? Is Breen dead? And what is the G-Man's involvement in all this?" The Citadel is about to be taken out in characteristically spectacular fashion - and is due to take the remnants of City 17 with it.
Episode One will therefore see a mad dash through the crumbling vaults and towers of Breen's former administration building, before showcasing its wrecked environs: awash with Antlions that have flooded into the wrecked city, panicked Combine troops and pockets of humans desperate to escape. Kleiner, meanwhile, has hacked into the Citadel's propaganda network and his face replaces the chiselled, furry jaw of Breen on City 17's manifold screens - delivering his own brand of dire warnings and crackpot theories, while on-screen violence between the resistance, enemy troops and the Antlions continues to erupt.
AXIS OF EVIL?
It's at this point, however, that we come across a revelation: there's some new faces in the ascendancy. "Episode One marks the rise of a third power in the HL2 universe and one that'll have a large impact on Gordon's future," explains Walker as we bring a crowbar to his usually tightly-shut jaw. A third power? The Vortigaunts? Well, Walker has elsewhere confessed to us that the doleful beasts will "play a very important role in what happens in later episodes" rather than initial ones, so a pro-active green energy burst from them is perhaps unlikely. Who then?
It could be an axis of power never seen before. Or, if we move slightly into conjecture, it could be the Combine themselves - pan-dimensional creatures such as that of the monstrous visage that we saw promising Breen a host body in the closing moments of Half-Life 2.
Our evidence for suggesting this lies in what Walker tells us next. "The Combine aren't happy with Breen's failure to deal with Freeman and the Resistance. In Episode One, you learn some of the ways in which they're starting to take things into their own hands, none of which is good news for Gordon and Alyx."
Don't forget, headcrabs perhaps aside, none of the creatures who met the pointy end of your crowbar last time were of direct otherworldly (or indeed other-dimensionally) origin, instead manufactured by Breen in the Citadel using the Combine technology granted to him in Xen's side of his Faustian pact. Voluntarily or extremely involuntarily, the soldiers, zombies and Citadel stalkers are all adapted humans: biological, mechanical and tech-hybrids pumped out by the monolithic Citadel.