Episode 4

Big Brother follows a group of people living together in a house outfitted with dozens of high-definition cameras and microphones recording their every move, 24 hours a day. Each week, the Houseguests will vote someone out of the house. At the end, the last remaining Houseguest will receive the grand prize of $500,000.

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.