The Misty Valley Branch Line goes from the Peel Godred Branch Line, south of Peel Godred to Lord Callan's Castle. Callan, Black Loch and Lord Callan's Castle are located here. Cyril the Fogman also lives close to this line in his cottage.
No engines have worked on this line, however during the fourth season Duck, Oliver, Donald and Douglas were often seen working at Callan. Thomas, Edward, Henry, James and Percy have also been working on the line. Emily worked the line for a while. This started in Emily's New Route, when she first saw Black Loch.