Mrs. Luttridge will look upon him as her dupe, and make him such.
It consists in locating and exploiting the organ that one is a dupe with.
If she fell, should he not save his friend from being the dupe of an artful intriguante?
One cannot even say that "her head is the dupe of her heart," since she has no heart.
In order to dupe the old man, he pretended to be in bad health.