The Light in the Swamp — Velda Johnston

The big old family house in the Long Island woods was filled with unhappy memories of an ancient scandal and a sisters' feud. Catherine Morrel had never been invited there had never even met her Aunt Marian or Marian's husband, Loren Hauklid. Recently widowed and almost destitute, Catherine had driven from Chicago with her five-year-old daughter Nicole, asking for temporary refuge until she could regain her strength. Grudgingly the Hauklids permitted them to stay.

From the first day, Catherine sensed strange undercurrents that could not be blamed on the troubles of the past. A frightened hatred seemed to swirl through the house like an invisible fog. Yet why should anyone fear her? Why were the Hauklids so hostile to trespassers, so eager to identify them? And what was the meaning of the flickering lights Catherine saw from her bedroom window at night? A killer would strike to keep the secret of the answer.