Edward Brennan Healy, 39, was the oldest man in his Navy squadron. He was almost the age of his pilot’s father. That, and the fact that he had eight children back home, probably helped earn him the nickname “Pop.”

A gunner on a B-24 bomber based in the Solomon Islands, Healy flew off into a South Pacific morning on his 67th mission on March 9, 1944. During the flight, he and the 10-man crew sent out a distress signal, then disappeared, somewhere near Kapingimarangi in the Caroline Islands. No sign of them was ever found.

But more than 66 years later, a few weeks before Memorial Day, a token from Pop Healy made its way back around the world to arrive in his son’s Stone Mountain mailbox.

“I’ve been in a business where I saw some pretty strange things,” said Joel Healy, a former police officer, “and this goes beyond strange.”

Joel’s brother, Michael Healy, 77, of Cedar Rapids, Iowa, said, “I tell you, I started crying as soon as I heard of it.”

Joel Healy, 71, who grew up in Chicago, was just 5 years old the last time he saw his father. The son doesn’t own a single letter from his father. The only photo he has comes from the Navy: a group picture of his dad’s squadron. But now he has something his father carried close to his heart: his dog tag....