Aubrey Plaza and David Letterman talk about both of their shows coming to an end. Now that her show Parks and Recreation is over, Aubrey in particular has some ideas about what she might pursue.

Aubrey surprises David Letterman when she reveals the story of the film she's in alongside Hollywood superstar Robert De Niro. The conversation then turns to drinking and the host talks candidly about his past.

A 14-year-old Natalie Portman talks with David Letterman and Alec Baldwin about starring in R-rated movies and getting straight As in high school.

Movie star and straight A student Natalie Portman has homework to do just like any other schoolgirl, and reveals that she sometimes finds herself in the same kind of trouble as a normal teenager.

Anne-Marie is a successful singer and songwriter, and she believes that all the hard work, discipline, and focus learned while becoming a black belt in karate has prepared her well for her busy life. She clearly loves her teacher Jo, and her sport, in which she has won gold medals at World Championship level.

The boys from the pop band The Vamps join Anne-Marie for a karate lesson. She takes them though a warm up, some kicking and punching, then a game and a sparring session that threatens to get out of control!

It’s radio presenter Roman Kemp’s turn to learn some moves from Anne-Marie. He sounds worried when she mentions “nunchucks” and “knife defense”, but he just isn’t taking his lesson seriously, and keeps distracting her. Eventually she suspects he’s done some karate before, and maybe isn’t such a complete beginner.

Anne-Marie shows us a section of a “Kata,” a series of defensive moves designed to fend off multiple attackers. Then she applies these techniques with Alex playing the role of the attacker as she demonstrates a part of the “Bunkai.”

Anne-Marie has fun teaching pop star Olly Murs a kick and a block to defend from that kick. Then he tries his hand with the nunchucks, but proves to be more of a danger to himself than to anyone else! Overall, he’s very good, and almost gets top marks for his first day of karate.

Actor Johnny Depp discusses his role and working with director Tim Burton in the 2005 film Charlie and the Chocolate Factory.

John has fond memories of exploring New York City with his father. He remembers the Chelsea neighborhood as an area where not much was happening — a "no man's land," as he calls it. However, it’s changed a lot since then.

John looks out across the Hudson River and explains the appeal of New Jersey for many residents who have recently moved there from New York City.

John talks about the importance of the city park, no matter how small, in the modern world. He enjoys the open space, fresh air, and sun on his face. He also likes the changing seasons, which mark the passing of time.

Central Park lies between the East and West Side of New York City, and today John is there by the frosty waters of the Jackie Kennedy Onassis Reservoir. It’s a popular place for New Yorkers to go jogging, and was once featured in a movie starring Dustin Hoffman.

In Central Park, John finds himself next to a sculpture of the Danish writer Hans Christian Andersen, author of some of the world’s best loved stories, including "The Ugly Duckling."