The $650 million merger of Nashville’s two biggest hospital companies, HCA and HAI, changes the industry and the Nashville health care community in a significant way and is a sign of what’s to come: decades of deals.

Combined, these companies control almost a fourth of all privately owned U.S. hospitals at the time.

The deal, which Thomas Frist Jr. reportedly orchestrated in less than 10 days, takes HAI employees and executives by complete surprise. Many of them, like Richard Ragsdale and Charlie Martin, take their stock gains and set out to start new companies — again.