We followed the supply chain for batteries used in millions of U.S. cars to villages in Nigeria where people are being poisoned by lead. Peter S. Goodman, who covers economics and geopolitics for The Times, describes our yearlong investigation.

Tariffs have forced Chinese companies to move their operations to Vietnam. Alexandra Stevenson, our Shanghai bureau chief, visits a factory in Ho Chi Minh City to see how one of the biggest challenges isn’t relocating machinery and tools, but overcoming language barriers.

David A. Fahrenthold, an investigative reporter, describes the struggles of the Sierra Club, one of the largest environmental groups in the U.S. The group has lost about 60 percent of its supporters since 2020.