Stranger In The House

Description for STRANGER IN THE HOUSE by Patricia J MacDonald:

WHAT DID HE SEE?
WHAT DOES HE KNOW?
Eleven years ago, Anna Lange's life was shattered when her young son, Paul, disappeared -- though she never gave up hope that he might be alive. Now, her son has been returned. The joyful family reunion is short-lived, however, as the nervous, withdrawn Paul begins to behave strangely. Anna's husband and daughter grow fearful living in the same house with him. But Anna believes that Paul is still recovering from the extreme psychological trauma he experienced the night he disappeared -- though he claims he has no memory of that time.
Does he or doesn't he? Someone remembers -- and will stop at nothing to keep the truth a secret. Now Anna will have to contend with a nightmare from the past that will either tear her family apart, or destroy them together....