My wife is an only child—who has six half-brothers she never knew. She grew up hearing occasional references to them from her father—who had lost contact with his sons for more than twenty years. When those stories got to me, I did a bit of sleuthing online, and with a little work and a few phone calls, tracked them down. She is now in regular contact with one brother, and starting to forge a relationship with some of the others. One died several years back; she never got to meet him.