Tomorrow night, in a collaboration with Marketplace, PBS Frontline presents "Big Sky, Big Money," an investigation into campaign finance and how the Supreme Court’s Citizens United decision has changed campaigns in America. Marketplace's Kai Ryssdal travels to Montana to examine the impact big money is having on the democratic process not just at the federal level, but in states and local communities.

Today, ProPublica and Frontline released their investigation on a box of stolen documents that were discovered in a meth house in Colorado in 2011, which play a major part of the "Big Sky, Big Money" investigation. The documents offer insight into "the growing influence on elections of dark money groups, tax-exempt organizations that can accept unlimited contributions and do not have to identify their donors." Read more about the documents here.

Then tune in to your local PBS station on Tuesday, Oct. 30 to see the hour-long documentary and learn more about this secret world of campaign financing.