Comedian and writer Ian Karmel joins Mark Malkoff to look back on his path from Chelsea Lately to becoming co-head writer and James Corden’s on-air comedic foil on The Late Late Show and beyond. He talks about creating “Crosswalk the Musical,” performing stand-up on Conan, working with Mel Brooks, Tom Cruise, and Ellen DeGeneres, and reuniting with Corden for this summer’s FIFA World Cup late-night show.