It is believed to be the world’s most valuable book but you may never have heard of it. And now it’s up for auction with an estimated sale price of between $15-$30 million. We tell you what the extremely rare and pricey tome is when we get a firsthand look at it in our studio on Tuesday.

We revisit Jay Shefsky's profile of a basketball team you won't forget. Read an article and view a photo gallery.

Watch Charlie Rose's exclusive interview with Syrian President Bashar al-Assad.

How is the CTA faring in day one of the rollout of the controversial new Ventra system? Paris Schutz has the details.

Illinois Rep. Jim Durkin talks about his new role as the minority leader of the Illinois House. View a timeline of his career.

Former Chicago Bears pro-bowl lineman James “Big Cat” Williams joins Ann Kreiter to kick off another season of Big Cat and the Bears. Watch a web extra video.

With regimes toppling in the Middle East and new global powers emerging, political transformations are challenging the notion of democracy as the best system of governance. In his new book, Intelligent Governance for the 21st Century, “homeless billionaire” Nicolas Berggruen explores perceptions and practices of both the East and West to find what constitutes good governance. Read an excerpt and an interview.

How do tech incubators work, and what’s the real story behind this growing scene in Chicago? Our panel of experts – from both universities and private incubators -- weigh in. View a map of tech incubator locations in Chicago.

We share your thoughts on Minneapolis Mayor R.T. Rybak's visit to Chicago in tonight's viewer feedback.

Eddie Arruza and his panel of journalists discuss the week's top headlines.

Eddie Arruza and his panel of journalists discuss the impact of TV host Stephen Colbert comparing Syrian violence to Chicago's. Also, they talk about the challenges and questions facing Illinois congressional members as they vote whether to authorize military action in Syria. Watch the web extra video.

A craft fair, classical music, and a half marathon in Jackson Park; Chicago Tonight knows what's going on this weekend.

On this edition of Chicago Tonight's Field Trip, we hit the road with The Field Museum’s Fossil Invertebrates Collections Manager to hunt for fossils from a time when Chicago was a tropical reef. Watch the video and view a slideshow.

We talk with Chicago Tribune reporter Bill Ruthhart about his story detailing business ties between a top aide in Mayor Emanuel’s office and the indicted city comptroller. Read Ruthhart's full story.

The Mayor of Minneapolis, R.T. Rybak, has come to Chicago to invite same sex couples to marry in his city. We talk with him about the unusual campaign, as well as his thoughts about Chicago's mayor.