Each demo was shocking, in its own way. The townhouse raid highlighted Infinity Ward's technical capabilities, showing off lush domestic scenes rich with details, all built via photogrammetry and microtiling in the latest iteration of the studio's proprietary engine (and running in-game on a PlayStation 4). Infrared wasn't just a green overlay on a dark screen; it changed the environment on a fundamental level, materializing a bike frame in a dark alley and lighting up reflective patches on Marine uniforms. Doorways and hallways were true to scale, making the townhouse feel claustrophobic and maze-like as a swarm of soldiers swathed in black armor prowled through a back doorway, weapons drawn.

Our soldier turned a corner to see a room of people talking over a dining table littered with papers. He paused before shooting out the central light bulb, activating infrared, and killing every character in sight. The NPCs reached for their weapons and gunshots rang out from adjoining rooms as other Marines cleared the house. The soldier carried on, shooting through walls and taking down enemies scrabbling for their own guns, the entire team around him murdering the Middle-Eastern terrorist cell with smooth precision.

It was like Rainbow Six: Siege on steroids; beautifully rendered, strategically designed and shockingly calm, for a scene filled with room after room of methodical slaughter. That's how the Marines and Navy SEALs do it, developers said, citing years of research and interviews with military consultants.

The second demo began under a pile of rubble. Small hands reached up and a young girl's voice coughed and broke as she pushed at the heavy stones crushing her. She turned her head and her mother's corpse stared back, bloodied and eyes blank. The girl called out, terrified, and clawed at the blocks, nearly making them fall in deeper and bury her, until a voice broke through from above and people began lifting stones away. A crew of people pulled her out and reunited her with her father on a frenzied street in a desert city that had just been bombed to hell.

The second demo began under a pile of rubble.

The explosions didn't stop; planes raced by overhead, dropping more bombs, and Russian soldiers on the ground shot wildly into crowds. The streets filled with poison gas. The girl and her father ran home, where they found her brother -- "Where's mom?" he asked, of course -- and prepared to flee and fight. A monster of a Russian soldier burst through the door, wearing a gas mask and carrying a rifle; the father fought him and lost, shot through the chest on the living-room floor. The children, alone now, scrambled for cover and weapons. The girl grabbed a screwdriver and stabbed it into the soldier's gut before running away, hiding around corners and crawling through vent hatches as he chased, grunting obscenities.

After a cat-and-mouse mini-game, the kids eventually killed the soldier, and then spared a moment to say goodbye to their dad, who lived just long enough to tell them he loved them. The children ran out of their house in gas masks. Noxious clouds filled the streets as they crept past corpses and Russian soldiers executing neighbors with quick, clear shots. They passed a dying dog, prompting the brother to comment on the invading soldiers' brutality. The children made their way to an enemy post, where the girl was forced to find a gun and shoot the surrounding soldiers.

This young girl grows up to be the protagonist in Modern Warfare. She and her brother adopt varying perspectives on their fight and how much of their humanity they're prepared to sacrifice for the greater good.