We replay sections from the original "Giant Pool of Money," in which This American Life producer Alex Blumberg teams up with NPR's Adam Davidson to tell the story of how the U.S. got itself into a housing crisis. They talk to people who were actually working in the housing, banking, finance and mortgage industries, about what they thought during the boom times, and why the bust happened.

We catch back up with the people we met in 2008, to see how they've fared over the last 18 months. We talk to Clarence Nathan, who in 2008 received a half million dollar loan that he said he wouldn't have given himself; Jim Finkel, a Wall Street finance guy, who put together and managed complicated mortgage-based financial securities; Richard Campbell, the Marine who was facing foreclosure; and Glen Pizzolorusso, the mortgage company sales manager who led the life of a b-list celebrity.

Planet Money reporter Chana Joffe-Walt asks a simple question: Who was the federal regulator who was supposed to be regulating AIG? The answer turns out to be far from simple.

Alex Blumberg and NPR correspondent (and "Planet Money" reporter) Dave Kestenbaum examine what went wrong with the credit ratings agencies. When all these financial instruments that brought down our economy—the mortgage backed securities, the derivatives—were originally issued, the rating agencies (Standard and Poors, Moody's and Fitch) gave many of these things their top rating of triple-A.

Ira goes to Chicago's Rogers Park neighborhood to talk to some condo owners who are in a precarious situation—since the housing market crash, the developer who renovated and sold them their units—Haso Meseljevic—has all but disappeared. He's in foreclosure on half of their building's units.

NPR reporter and Planet Money contributor Chana Jaffe-Walt reports this story of what it really looks like when a bank fails and is taken over by the FDIC. She talks to the former employees and a handful of FDIC staff about the Friday night when the Bank of Clark County was interrupted and closed by 80 FDIC employees, who had every step of their secret operation down to a science.

Alex Blumberg and Adam Davidson tackle a very tough subject: Trying to explain exactly what a bank is and does. They talk to a number of experts about what has gone wrong in banking, but not before bringing us all up to speed on some banking basics, like understanding a bank balance sheet, and a bank's assets and liabilities, and the squishy business of what banks say about their balance sheets compared to what they are.Alex and Adam walk us step by step through the complications of the US government buying up bad assets from banks, and explain why, when it comes to footing the bill, the government might just prefer to not be in charge of the very banks it is having taxpayers bailout.

Not everyone hates the idea of "toxic assets." Reporter Lisa Chow goes to New Jersey to follow two guys on their quest to clean up some of America's bad mortgages—by buying them, and going straight to the homes themselves to have a look at how dire the situation really is.