After her miscarriage, much of the hostility from the family evaporates, with the exception of J.R. He openly despises her and her brother. In 1979, Pam is told by Digger's doctor that Digger was a carrier of neurofibromatosis, and that she and Cliff, as his children, were carriers; as neurofibromatosis is a potentially fatal disease to infants. Ironically, Pam soon discovers she is pregnant again. As before, however, tragedy strikes as a rattlesnake frightens Pam's horse when she is out riding and throws her, causing a second miscarriage. In 1980, Pam watches Digger die slowly and painfully as a result of his decades of heavy drinking. On Digger's deathbed, he tells Pam that she's not his biological child, but born after an affair her mother Rebecca (Priscilla Pointer) had with Hutch McKinney (William Watson). Overwhelmed by a sense of loss after Digger's death and deathbed confession, she pushes to find out more about what happened to her mother. She develops a notion – a dream born out of grief – that perhaps her mother isn't dead after all. Then a private investigator turns up evidence that her mother had not died as Digger had believed, but was alive in Houston. Meanwhile, Bobby has taken over Ewing Oil while J.R. is convalescing after being shot. Pam watches her husband get deeper and deeper into the heart of business in an effort to prove himself, and takes note of Bobby's instinctive attraction to power, which she realizes might be a danger to their marriage.