A negative productivity shock hits the global economy, and various bad consequences ensue, including The Idea Trap. Behavioral factors exacerbate the course of events. Some degree of mean reversion ensues, to specify that degree would involve spoilers. OLG models remain relevant, indeed more relevant than most others are willing to believe. The rest is detail.
I am often skeptical of Christopher Nolan movies for lacking heart, but I enjoyed this one more than I expected to. It would have been better, however, if no character had been allowed to articulate any propositions of physics.