In the Know

20/20 continues to combine hard-hitting investigative reports, newsmaker interviews and compelling human interest and feature stories.

Literature professor Harriet "Harry" Wild is adjusting to retirement when she's mugged. While recovering at the home of her son, a detective in the Dublin police, Harry gleans a clue for his current case. But when she's rebuffed, Harry decides to solve the crime herself. Recruiting an unlikely young sidekick, she finds a new path as a private investigator.

Ancient Aliens explores the controversial theory that extraterrestrials have visited Earth for millions of years. From the age of the dinosaurs to ancient Egypt, from early cave drawings to continued mass sightings in the US, each episode in this hit History series gives historic depth to the questions, speculations, provocative controversies, first-hand accounts and grounded theories surrounding this age old debate. Did intelligent beings from outer space visit Earth thousands of years ago?

American Ninja Warrior is an action-packed series that follows competitors as they tackle a series of challenging obstacle courses in both qualifying and finals rounds across the country. Those that successfully complete a course in their designated region move on to the national finals round in Las Vegas, where they face a stunning four-stage course modeled after the famed Mt. Midoriyama in Japan.

With the most powerful clients in Europe, MobLand will see family fortunes and reputations at risk, odd alliances unfold, and betrayal around every corner; and while the family might be London's most elite fixers today, the nature of their business means there is no guarantee what's in store tomorrow.

MobLand follows two generations of gangsters, the businesses they run, the complex relationships they weave and the man they call upon to fix their problem.