If there's one thing we learned from this week's revelation of the Panama Papers, it's just how internationally interconnected illicit shadow money is. A corrupt Brazilians politicians goes to a law firm in Panama, and then builds a couple of skyscrapers in Miami, for example.

And much of that web, an estimated 40 percent of it, originates with global arms deals, which is the subject of a timely new film premiering at the Tribeca Film Festival: "Shadow World." 

Andrew Feinstein wrote the book the film is based on. He stumbled into the world of the arms industry when he was a politician in South Africa, a member of the ANC Party under Nelson Mandela, and then began an investigation into a 10 billion dollar arms deal made by his party. He found that $300 million were bribes, much of which went to government officials. 

He joins The Takeaway to discuss the book and his film, and what the Panama Papers reveal about the global arms trade. 

"Shadow World" premieres on Saturday, April 16th, at 9:15pm in Regal Cinemas Battery Park Stadium 11.