How did PFAS, the forever chemicals once used in popular stain-resistant carpets, end up in the water and environment in parts of Georgia, Alabama and South Carolina? FRONTLINE, The Associated Press, The Atlanta Journal-Constitution, The Post and Courier and AL.com investigate what happened and the ongoing health impacts.

An examination of Salvadoran President Nayib Bukele’s deal with President Trump to imprison U.S. deportees, and what each leader stood to gain. FRONTLINE and the Salvadoran news outlet El Faro, now operating in exile, investigate Bukele’s tangled history with the gangs the U.S. says it is fighting.

FRONTLINE and ProPublica trace the violence, protests and arrests stemming from federal immigration sweeps across the United States. The documentary examines the tactics, legal cases and impact — from Los Angeles to Chicago to Minneapolis.

President Trump's unprecedented challenges to the Federal Reserve and what it means for the economy; tracing the battle between Trump and the Fed as the central bank steers the economy through an increasingly precarious moment.

The key players behind President Trump’s expansive use of the U.S. military. From clashes with allies, to taking out foreign leaders, to waging war in the Middle East, examining the inner circle of advisors and officials trying to project U.S. power.

Have lax laws left the for-profit adoption industry ripe for misconduct? FRONTLINE and Retro Report investigate how so-called baby brokers have targeted pregnant women and families looking to adopt, and an epicenter of the problem in Utah.

FRONTLINE examines the alliance between Saudi Crown Prince Mohammed bin Salman and President Donald Trump. Based on more than 100 interviews done by correspondent Martin Smith, the documentary examines the forces binding the two men and their countries together, and what each stands to gain — from ambitions for a new Middle East, to arms deals, investments and personal profit.