The Old Castle's Secret is a comic story written and drawn by Carl Barks. It features Donald Duck, Scrooge McDuck, Huey, Dewey and Louie Duck and Diamond Dick. Sir Quackly McDuck is mentioned several times and impersonated by Diamond Dick (as is Scottie McTerrier).
Scrooge McDuck has a new project. He has known since he was a child that somewhere in Castle McDuck, the lost treasure of Sir Quackly McDuck is hidden. All past searches by members of the clan have been unsuccessful, but Scrooge thinks that with modern technology such as X-rays to scan the walls, it will be a child's play to find the loot. However, when they arrive, they are opposed by what seems to be the ghost of Sir Quackly himself, who seems very intent on keeping the treasure to himself…
- During the events of The Old Castle's Secret, the "McDuck fortune" was not doing so well, at least according to Scrooge McDuck.
- Scrooge states that his family has kept secret the treasure of Sir Quackly McDuck for 900 years. He later states that Quackly disappeared with the treasure in 1057, indicating that the story takes place roughly around 1957.
- Castle McDuck is located in Dismal Downs, Scotland.
- The names and death dates of several medieval McDucks are revealed. Among these are: Sir Eider McDuck, who died in 946 at the hands of the Saxons; Sir Quackly McDuck, who disappeared during a siege in 1057; Sir Roast McDuck, who overrate himself to death in 1205; and Sir Swamphole McDuck, who sealed the dungeons of Castle McDuck in 1220 and would not be buried in the castle's cemetery.
- Scottie McTerrier was the caretaker of Castle McDuck and died just a few months before the events of The Old Castle's Secret. He would then by impersonated by jewel thief Diamond Dick.
- The Old Castle's Secret would be remade into the 1986 painting, Dubious Doings at Dismal Downs, which reveals the name of two new McDuck ancestors, Friar Juicy McDuck (910 - 971) and Sir Smokt McDuck (b. 930). It would also establish Swamphole McDuck as having lived from 1161 to 1221.
- Johannes A. Grote's Duck family tree (1999) would use a portrait seen in Scrooge's mansion in this story to represent Fergus McDuck.
- A Letter From Home (2004) was written as a sequel to The Old Castle's Secret and reveals that Matilda McDuck was hired as Castle McDuck's new caretaker in the aftermath of the original story. Hints are given here as to when The Old Castle's Secret took place. The story indicates that the last time Scrooge saw Matilda was during the events of The Empire-Builder from Calisota. Matilda says that is has been "nearly 25 years" since then. A flashback to that story occurs later and shows a graph with the date "1932", indicating that is the fallout occurred. This would mean that 1957 is the latest date The Old Castle's Secret could have occurred, since it must have taken place before A Letter From Home, which takes place almost but not exactly 25 years since The Empire-Builder from Calisota, which takes place around 1932.
Behind the scenesEdit
This story was first published in Dell One Shots #2, titled Donald Duck even though it is not officially part of the Donald Duck line. It was reprinted in The best of Donald Duck and Uncle Scrooge #1 in 1964, then also in Best Comic Series #4 and in Best Comics #180 (as Uncle Scrooge and the Secret of the Old Castle). It was then reprinted in the various versions of the Carl Barks Library.