A relationship between a young woman and a giant 30ft tall bird thing could be messy," says Ken Levine after our breathtaking 15-minute demo of Bioshock Infinite rolls to a close.
He's talking, of course, about the link between starlet Elizabeth and the towering Songbird who's both kept her captive and kept her company for most of her life. The Songbird is her jailor and her protector, and won't let anybody come between it and her - even you.
"I was talking to a friend of mine," explains Levine, "and he said the Big Daddy was a god of the ocean and so the Songbird needs to be a god of the sky. He has to be huge and overwhelming, and this 30ft tall thing has to have an intense, strange, weird relationship with Elizabeth. And that's what we want to do. Relationships are messy and I don't just mean romantic relationships: just people's relationships."
Our walkthrough begins with Elizabeth and Booker picking their way through a deserted Major Notion's Sundries and Novelties shop. The first thing that hits us isn't the sunlight streaming in through the windows (although it's a welcome sight after Rapture's total dependence on electric-powered illumination) but Booker DeWitt's voice.
It's odd to hear a Bioshock protagonist speaking outside of an intro video, let alone engaging in a full-on conversation with a partner who's persistently on screen.
As Booker and Elizabeth weave through the shop they're always conversing. Sometimes Elizabeth will be joking about - parading around with an Abraham Lincoln mask on while reciting the Gettysburg Address - and Booker will be chuckling; other times she'll be marvelling at the USA paraphernalia on show and Booker will simply be calming her down.
If Booker's not close enough to Elizabeth for these moments to kick in they won't happen, but that's okay - you won't necessarily miss out. When the pair are in close enough proximity to one another the next time she passes by the items needed to trigger these unique reactions, even if it's not until hours later into their journey, they'll happen then.
Much later on when the duo are caught up in a major battle they're still talking to one another - about combat tactics this time - but for now the chit-chat is jovial as Booker ransacks the shop for gear and cash: pinching dollars from the till, a Vigor from a shelf and a Nostrum from a barrel. As Ken says, Irrational are really playing on the relationships.
Vigors and Nostrums are Infinite's equivalent of Plasmids and Tonics. Booker snaffles a Bucking Bronco Vigor that lets him pull objects and people up into the air to either shoot them or force-push them away, and a Pot Luck Nostrum that lets him choose between a Spring-Heeled movement speed increase power, a Winter's Shield Sky-Line bonus or an Executioner melée upgrade. The selection's handled with the face buttons, and at no point does he need to enter a menu system to equip them.
The ransacking is soon cut short by an interruption from none other than the Songbird. It lands outside the store windows with a crash that upends half the knick-knacks in the shop, and its green eyes turn a threatening shade of orange as it scans the insides of the building looking for life. Elizabeth ducks behind a counter and stifles a scream.
Booker quickly crouches by her side and out of sight. When the bird gives up looking and leaves in search of other hidey-holes, Elizabeth breathlessly explains how she'd rather die than fall back into its capture before daring to venture back outside.