Discontent was brewing among the laboratory staffback in Shenzhen. Dr. He was on the road—traveling to Beijing, California, and Hainan to tell trusted supporters about the birth and to plan grand new ventures—while the laboratory staffwere still trying to figure out if the babies would be okay. He was charging ahead at a moment when care and caution should have been taken. The twins remained in hospital incubators, wearing masks to help them breathe, while the laboratory ran tests and crunched numbers. The technicians were still poring over their DNA sequences, trying to see if the babies suffered any genetic damage from the experiment.

The lab had been preparing for a birth in late November or early December. When the delivery came prematurely, everyone had to scramble—readjusting the time they were dedicating to other projects, shifting to new urgent priorities. The genome editing summit in Hong Kong was just weeks away, scheduled to kick offon Monday, November 27, 2018. Pressure was mounting to analyze the data and submit a paper for publication. The staffreasoned that it would take at least ninety days to make sure that the twins were healthy and to prepare the paper. Through a variety of tactics—diplomacy, subtle persuasion, and open confrontation—the laboratory team tried to convince Dr. He to slow down his publication timeline. In spite of their urging, he kept pushing for speed.

As the DNA sequencing data from the twins trickled back into the laboratory, it fell primarily on the shoulders of one person to make sense of the code. A star undergraduate student in Dr. He's bioinformatics course, whom I will call Goran, was hired into the laboratory straight after graduation. The young computer whiz spent long hours hunched over his keyboard in a tiny office on the SUSTech campus he shared with a junior bioinformatics technician and the contact person for patients in the study. His lab mates thought of Goran as wise beyond his years. When Ryan Ferrell joined the team, the young technician slid his computer over so that the pair could share a desk. Goran liked to keep his sideburns long, down past his jawline. He routinely wore earbuds with music playing—even when Dr. He would sit down to have a one-on-one chat.