Samille Sweeny is a moderately successful landscape and still life artist whose popularity is surging. Her works sell well at an exclusive gallery in New York City, and she has become friends with Chandra Worth, a co-owner of the gallery. Samille lives contently on the St. Lawrence river, devoting herself to her work and living a normal life until one September when she feels herself begin to change.
The changes are unnoticeable at first, colors are brighter, plants bloom, her painting is more vivid. She begins to dread winter and sublets an apartment in New York City for a change of pace. She starts a relationship with Richard Worth, Chandra's estranged husband. She also starts having a recurring dream of a murder which she eventually paints. She continues to work on the murder painting as more details come back to her and then Chandra is killed.
Richard and Samille are suspected but both have alibis. Then an attempt on Samille's life occurs and the killer is after her.