Episode Four

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.

Murders and mojitos. Fresh off the plane, a British detective joins the police force on the luscious Caribbean island of Saint Marie.

Flying is one of the safest forms of transport. But what happens when tragedy strikes? From human error and accidents to mechanical faults and design flaws, the success of aviation history is punctuated with disaster and catastrophe. It's rare, but it does happen. Follow experts as they determine what went wrong and work out how to prevent these horrific tragedies from happening again. Examine the wrecks and official records, and hear from eyewitnesses, passengers and aviation experts as we reconstruct some of the most tragic disasters in aviation history. Air Crash Investigation looks at what went wrong and how future disasters can be averted.

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

Sister Wives explores the complex daily life of a polygamist family. Sister Wives introduces audiences to husband Kody -- along with his three wives; Meri, Janelle and Christine and their combined 13 children -- showing how they attempt to navigate life as a "normal" family in a society that shuns their lifestyle. From their unconventional family structure and living arrangements to financial challenges, each half hour episode exposes the inner workings of a polygamist household, revealing the unexpectedly tight-knit and loving relationships between Kody's wives.