This reminds me of an account of a Christian martyr, in Roman Carthage around 200 AD. The young Christian Woman told the Roman soldier that she forgave him and that she would come to him to show there was life after death. She did so and he converted to Christianity, and was himself martyred. Unfortunately I don’t know the name, but remember being told it during a study of very early Christianity.
Hopefully someone out there also knows of this and can fill in the blanks I’ve left.
I think this is the account you mentioned:
http://bswett.com/1998-12Potamiaena.html