They got up a few more flights in a back stairwell before Happy paused and gestured for the kid to climb up onto his back. He figured they'd move a lot faster that way and he wouldn't have to keep looking around to make sure Alex was keeping up. When the kid was safely on his back and took off running again, huffing and puffing up the stairs and thankful that he'd been hitting the gym every day before this all started. It definitely helped now.
As they burst out into the penthouse floor the building's steady shake became a rattle that made the floor buckle and sent Happy sprawling, the kid tumbling off his back. "Pepper!" he shouted, scrambling to his feet again and make a mad dash through the rooms as the floor rolled like a ship deck in a storm. "Pepper!!" There was nobody in their bedroom or any other room he checked. He went from door to door, throwing them open and finding it all empty. Where was she? Where was Anthony? Maybe they'd gotten out, he hoped to god they'd gotten out.