It was a terrible tragedy which first brought Rosy Smith to Derwent House, the grand home of John Hardaker and his wife Dorothy.The loss of one of their twin baby sons in a mysterious accident meant that Dorothy no longer found herself capable of caring for the surviving twin, Nicky - so Rosy, only sixteen but full of love for the helpless child, had to step into the breach. As the years went by and Dorothy became less and less able to deal with life, Rosy's mother Nell, the housekeeper, watched with trepidation as John Hardaker's interest in his young nanny became noticeably warmer.

In time, Rosy became the mistress of Derwent House, but her new position brought her, not the happiness she longed for, but unexpected misery and yet more tragedy.The old family house was to see many changes and revelations before Rosy could at last find contentment.