Five years after the Federal Reserve and Treasury allowed the investment bank Lehman Brothers to fail, while rescuing Bear Stearns, Fannie Mae, Freddie Mac, and AIG, their actions (or inaction) remain a focus of debate. Cline and Gagnon present evidence that federal officials, at least in hindsight, appear to have followed the dictum of Walter Bagehot that lending should be granted only to solvent entities. Lehman was insolvent—probably deeply so—whereas the other institutions arguably were solvent. The other institutions had abundant collateral to pledge, whereas what little collateral Lehman had to pledge was of questionable quality and scattered across many affiliated entities. While the Fed and Treasury had a sound reason to let Lehman fail, the shock to financial markets that ensued from its collapse sent the financial crisis into a new, more acute phase and may have contributed to the severity of the Great Recession. Therefore the lesson from Lehman is not only that Bagehot-type lender-of-last-resort action is as important as ever but also that it is critical to ensure an orderly resolution for a systemically important financial institution going bankrupt.