Based on a personal family history experience, in this paper, I consider the way in which genealogical DNA testing is revealing family secrets, in particular paternity secrets, which would previously have remained unknown via ‘traditional’ methods of genealogical research. Reasons for the displacement of these invisible fathers from the records are discussed, and the power of genealogical DNA testing to bring them into focus is examined. Such discoveries may disrupt and unsettle, causing people to think differently about the fathers and grandfathers with whom they have grown up or have believed to be part of their personal histories and, for some people, may challenge their sense of identity. Beyond personal identity issues, in this paper, I draw upon ideas about ‘ghost-work’ to suggest that these experiences have some of the features of hauntings and that the ghostly fathers who break through may speak to us about social realities and structures, beyond the confines of linear time.