After finding out that Denny was his grandson, "Virgin River" fans watched Doc take a trip down memory lane. Denny revealed to Doc that he was the grandson of a woman named Rose Miller, who was the physician's girlfriend before he went to medical school. Doc remembered Rose and was stunned to learn that she had become pregnant with his child without telling him about it.

Rose went on to welcome the pair's son, Denny's father. Sadly, Denny revealed that his dad had passed away just a few weeks before he came to Virgin River to meet his grandfather (via Today). Doc was heartbroken that he was unable to meet his son, but was happy to get to know his grandson. In addition, the boy told his grandfather that his grandmother Rose was still alive, leaving more room for the story of Doc's unknown son to be told in the future, possibly with more proof to confirm Denny's story.

In addition to the death of his father, the new Virgin River resident also admitted that his mother was also deceased. This left him with very little family and a yearning to get to know his paternal grandfather. While Denny's story seems to prove that he is, in fact, Doc's grandson, his behavior raised some other red flags during Season 4 of the show.