Our family Bible went missing - many cousins knew of its existence, but no-one knew where it was, and it was turned up by a half-cousin that no-one in the family knew. My g. grandmother (the one who had put family history into a Bible which was presented to her on her wedding day) had married again after my g. grandfather died, and the Bible passed down through the children of this second marriage.
I made a contact through Genes Reunited with a descendant from this second marriage, and I mentioned the existence of this Bible, and at the time she didn't know where it was either. A few weeks later she was helping her sister go through her late mother's effects, and she saw this tatty old book in a black sack which her sister was going to put in the bin, and she rescued it, and it was the missing family Bible. Had I not made this contact a few weeks before, it's likely that the Bible would have ended up as land-fill
The inscriptions in the book were a little disappointing at first - just a lot of scribbled names and dates, when I was expecting a traditional family tree, but as time went by I began to appreciate the value of it. Inside were the names of all the children she had, including her first-born twins who only survived a few months, and who probably no-one else in the family knew about. The Bible now resides with the eldest cousin in the family, and the family history entries have been scanned and now feature on my Ancestry tree. And the half-cousin that nobody knew is now a wonderful friend to many of us in the family.