...Catherine's imaginings of the villain quickly riding off in a carriage with the heroine as a hostage.

Manfred was so quick to jump to his conclusion that as a reader, you feel that quick pace that rightly mirrors the concept of "running off" with someone.

It certainly would make sense for Catherine to link the General and Manfred. At least she seems to when she first arrives at the Abbey and begins to think the General may have killed his wife. Manfred was so eager to cast his wife aside (for not producing him anymore sons) that it wouldn't be a huge leap for Catherine to imaging the General offing his wife. Of course, in Catherine's story, when she actually is run off by the General she doesn't even make the connection at all. A good illustration of her growth.