His case is distinctive within it because of the Bourdin imposture, which added a dimension that almost no other cold missing persons case possesses.

But the underlying situation — a child gone without explanation, a family left in permanent uncertainty — is not unusual.

For the families of the long-unresolved missing, the experience described in relation to the Barclay case — the suspended grief, the inability to mourn definitively, the toggling between hope and despair — is not unique to them.

It is a widespread and underacknowledged form of sustained suffering.

The work of cold case investigators, and the increasingly sophisticated use of genetic genealogy and other forensic technologies to identify remains and connect them to missing persons, has begun to resolve some of these long-standing cases.