The Knock - Season 2

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

NCIS (Naval Criminal Investigative Service) is more than just an action drama. With liberal doses of humor, it's a show that focuses on the sometimes complex and always amusing dynamics of a team forced to work together in high-stress situations. Leroy Jethro Gibbs, a former Marine gunnery sergeant, whose skills as an investigator are unmatched, leads this troupe of colorful personalities. Rounding out the team are Anthony DiNozzo, an ex-homicide detective whose instincts in the field are unparalleled and whose quick wit and humorous take on life make him a team favorite; the youthful and energetic forensic specialist Abby Sciuto, a talented scientist whose sharp mind matches her Goth style and eclectic tastes; Caitlin Todd, an ex-Secret Service Agent; and Timothy McGee, an MIT graduate whose brilliance with computers far overshadows his insecurities in the field; Assisting the team is medical examiner Dr. Donald "Ducky" Mallard, who knows it all because he's seen it all, and he's not afraid to let you know. From murder and espionage to terrorism and stolen submarines, these special agents travel the globe to investigate all crimes with Navy or Marine Corps ties.

Poker Face is a 10-episode "mystery-of-the-week" series following Natasha Lyonne's Charlie Cale, who has an extraordinary ability to determine when someone is lying. She hits the road with her Plymouth Barracuda and with every stop encounters a new cast of characters and strange crimes she can't help but solve.

In this workplace comedy, a group of dedicated, passionate teachers — and a slightly tone-deaf principal — are brought together in a Philadelphia public school where, despite the odds stacked against them, they are determined to help their students succeed in life. Though these incredible public servants may be outnumbered and underfunded, they love what they do — even if they don't love the school district's less-than-stellar attitude toward educating children.

Based on an international hit, which already is a viral phenomenon with more than half a billion fans worldwide, and the No. 1 top-trending video of 2017 on YouTube, The Masked Singer features celebrities facing off against one another with one major twist: each singer is shrouded from head to toe in an elaborate costume, complete with full face mask to conceal his or her identity. Ken Jeong, Jenny McCarthy, Nicole Scherzinger and Robin Thicke serve on the panel and play detective, alongside host Nick Cannon.