Condolences go out to David Tennant on the passing of his father. I saw him recently in an NTA Special Recognition Award presentation given to David and he seemed a very sweet man and absolutely proud of his son. At least they got to appear together in an episode.
http://www.radiotimes.com/news/2016-03-18/did-you-know-david-tennants-dad-made-a-cameo-appearance-in-doctor-who
