The Intruder (1997)

When Catherine first moves to Canada from Europe she doesn't know anyone, and so when she meets Nick, romance quickly develops. Soon Catherine and Nick are married and living in his beautiful apartment building. Catherine's new neighbors are all friendly and intelligent and the she is no longer lonely, but there is something strange. Nick's previous wife, Stella, died two years before and was apparently murdered. As more and more clues surface, Catherine becomes fearful and begins to question if Stella is really dead.