Earlier today, the news broke that Peter Theo Curtis, an American who had been held hostage in Syria since 2012, has been released by his captors. Coming just days after another American hostage, James Foley, was brutally beheaded by the Islamic State, Curtis’s freedom brings a sense of relief.

The details of Curtis’s captivity and release reveal much about how al Qaeda is operating nearly thirteen years after the 9/11 attacks. It is not an accident that Curtis’s fate differed from Foley’s.