This was certainly downhill after The Lodger. I wonder what audiences of the era thought looking at Ivor Novello failing to look remotely like a youngster. A horrible story that didn’t even bother to give Mabel a clear motive apart from being a rotten woman. No amount of nifty directorial flourishes can drag this from near the bottom of the Hitchcock pile.
Alma fact: not credited but unlikely not to be involved
Appearance by a cat or dog: one cat
Trains: none but there is a lengthy sequence on a boat
Source: Alfred Hitchcock – The Early Years DVD (Concorde Video)