I first read Doom Castle years ago when I was in high school, and though I remember enjoying it, a recent re-read proved that almost none of the plot stayed with me over the years- most likely because I found the prose excessively wordy and difficult to get through. Since I now possess a much wider vocabulary than I did as a teen, I found the book much more comprehensible on re-read, although several aspects such as the historical setting and Scots dialect were mostly lost on me (not being Scottish myself).
Doom Castle tells the story of a Frenchman, Count Victor Montaiglon, who arrives at the titular castle in Scotland in search of a traitor whose actions caused the death of Montaiglon's lover. Eventually he loses motivation on his quest for justice when he becomes taken with Olivia, the daughter of Baron Doom, who is engaged in a love affair with the Duke of Argyll's Chamberlain, Simon MacTaggart. Through this acquaintance, Montaiglon unexpectedly finds his search fulfilled.
I loved the first half of this book, concerning Montaiglon trying to find out more about his hosts at Doom, which happens to be plagued by mysterious assailants in the night and whose owner wanders the house when the rest are sleeping, dressed in the tartan which he is forbidden to wear. The tension builds over the course of several chapters, and suspense rises with Montaiglon's suspicions that his host is shadier than he appears. I also found these chapters to be among the most humorous, as Montaiglon is a light-hearted and entertaining protagonist. Doom's servant Mungo Boyd also helpfully provides comic relief (although his written dialect confounded me on several occasions). Simon MacTaggart immediately presents himself as an intriguing and alluring character, and I confess I fell under his spell myself.
However, I found that the plot could have been less predictable. As it turns out, Doom is exactly the honorable man he claims to be, and it's MacTaggart who's the real scoundrel- the very one Montailgon is searching for, in a convenient turn of events. I was somewhat disappointed by the one-sided nature of the conflict, since the moment MacTaggart is revealed to be the leader of the assailants on Doom, suddenly it felt like every character was coming out of the woodwork to denounce him. I felt that turn came out of nowhere. He was a complex villain, but the problem was, he didn't feel like a villain at all until that point. I also thought the last few chapters wrapped everything up far too quickly and conveniently. I could have done with a few more chapters dealing with the fallout of the revelation of MacTaggart's wickedness, and the Lamond family preparing to leave Doom.
That isn't to say that the entire second half of the book was without merit, however, because there were certain points I enjoyed. "The duel on the sands" provided satisfactory action, and Montaiglon's flight from the lockup and his encounter with the Duchess of Argyll was simply hysterical. I also liked that Munro let Olivia and Montaiglon's romance develop a little more than I had expected it would. These factors add up to an overall enjoyable story, though I still feel the ending was rushed.