The battle to drive ISIS out of Iraq’s second-largest city was brutal and grueling. Shot over the course of the nine-month battle, “Mosul” follows one Iraqi special forces unit as they lead the fight. Also in this two-part hour: “Inside Yemen” offers a rare, up-close look at the country that’s home to what the United Nations recently called the world’s largest humanitarian crisis.

FRONTLINE tells the inside story of how Vladimir Putin came to see the United States as an enemy — and why he decided to target an American election.

FRONTLINE tells the inside story of how Vladimir Putin came to see the United States as an enemy — and why he decided to target an American election.

In 2012, FRONTLINE spent months following four young children as their families struggled with financial ruin. This documentary revisits the families to see what their lives are like now, offering a powerful, firsthand look at what poverty means to children.

The intimate stories of refugees and migrants, caught in Europe’s tightened borders. Amid the ongoing migration crisis, the film — a sequel to the award-winning 2016 documentary, Exodus — follows personal journeys over two years, as countries become less welcoming to those seeking refuge.

Some 25 dead bodies have been found on Long Island since 2016, all linked to the violent gang MS-13. Numerous immigrant teens are missing. As law enforcement tries to stop the gang, FRONTLINE goes inside the crackdown — investigating how the slew of gruesome killings led to many immigrant teens being accused of gang affiliation and unlawfully detained.

FRONTLINE investigates how a dangerous political rivalry between Iran and Saudi Arabia has plunged the Middle East into sectarian war.

FRONTLINE investigates how a dangerous political rivalry between Iran and Saudi Arabia has plunged the Middle East into sectarian war.

FRONTLINE investigates how Harvey Weinstein allegedly sexually harassed and abused dozens of women over four decades. With allegations going back to Weinstein’s early years, the film examines the elaborate ways he and those around him tried to silence his accusers.

FRONTLINE goes inside President Trump’s high-stakes battle for control of the GOP, examining how he attacked fellow Republicans and used inflammatory rhetoric that rallied his base and further divided the country in his first year as president.

Inside John McCain’s complicated relationship with President Donald Trump and his own Republican Party.

FRONTLINE and the Investigative Reporting Program at U.C. Berkeley tell the inside story of Guatemalan teens who were forced to work against their will on an Ohio egg farm in 2014.

FRONTLINE and NPR investigate the humanitarian and economic crisis in Puerto Rico after Hurricane Maria, examining how the federal response, Wall Street and years of neglect have left the island struggling to survive.

An investigation into sex abuse by United Nations peacekeepers in the world’s conflict zones. Award-winning correspondent Ramita Navai (Iraq Uncovered) traces allegations from Congo to the Central African Republic, with firsthand accounts from survivors, witnesses and officials.