Beijing's wai mai drivers: Delivering dumplings and living to tell about it

He Zhigang's eyes pleaded with the elevator dial as he stood waiting on the ground floor. The red numbers wouldn't budge. He glanced at his phone. He pushed back his helmet, lifted the delivery bag of steamed buns and prepared to run up 20 flights of stairs. The hungry office worker probably won't remember who brought him lunch on a Friday afternoon, or that it was 11 minutes and 20 seconds before the allotted time.