David Sanger, a White House and national security correspondent, describes how the crown prince of Saudi Arabia, a pariah after the killing of Jamal Khashoggi, has become a dealmaker in Washington.

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.