Explain the title and the ending

The friendship between the Langs and the Morgans begins with several rescues. The Langs rescue the Morgans more than once in those early years, but ironically, as the years go on, it is clear that the Langs are in need of rescue because their marriage is faltering, having gotten off on the wrong footing. Now at the end of Charity's life, the Langs need rescue more than ever, and the Morgans are there to help them.

Sally rescues them by trying to fulfill Sid and Charity's individually while restoring their dignity as a couple. Larry rescues them by being a sounding board for Sid when Sid is at his wit's ends and then by searching for Sid, being a support for him when Charity leaves for the hospital without him. Years of trial and struggle have given the Morgans the strength to deal with difficult times, and that experience is exactly what the Langs need as Charity is dying.