The Secret(s) of Castle McDuck is a cartoon story written by Bob Snow (along with DuckTales 2017's normal team of writers) and directed by Matthew Humphreys. It features Scrooge McDuck, Huey, Dewey, and Louie Duck, Fergus McDuck, Downy O'Drake, Webby Vanderquack, Launchpad McQuack, the ghosts of Sir Eider McDuck, Sir Swamphole McDuck, Sir Simon McDuck, Quagmire McDuck, Sir Roast McDuck, Sir Hugh Seafoam McDuck, and Molly Mallard, and the Devil Dog of Castle McDuck. Della Duck, Donald Duck, "Dirty" Dingus McDuck and Murdoch McDuck are also mentioned.
Scrooge takes his family on a trip to his ancestral castle to search for the treasure of the Knights Templar, however, he must first prove to his parents (mainly his father) that he is worthy of it. Meanwhile, Dewey believes that he may have discovered another piece to the puzzle of what happened to Della Duck.
Behind the scenes
The Secret(s) of Castle McDuck is the 21st episode of DuckTales 2017, and was released on August 4, 2018.