In a Glass Darkly: an Agatha Christie Short Story

The narrator is startled by a vision in his mirror. He sees a man with a scar on the left side of his face strangling a beautiful blonde woman. He later meets Sylvia, and realizes she is the woman of this terrible vision, and notes her fiancé has a scar exactly where he saw it. He tells her of his premonition, and the engagement is soon broken off. Is that all there is to the story or is there more?

Librarian's note #1: the story was published in the print anthologies The Regatta Mystery and Other Stories, and Miss Marple's Final Cases.

Librarian's note #2: this entry is for the story, In a Glass Darkly. Collections and other short stories by the author are located elsewhere on Goodreads. The author's stand-alone short stories, those without a lead character such as Hercule Poirot, can be found by searching Goodreads for: an Agatha Christie Short Story.