Janice Rule plays school teacher Helen Foley, who, after returning home from work, is confronted by a talkative little girl named Markie(played by Terry Burnham) who looks strangely familiar, but Helen just can't place her, despite Markie's constant prompting. Then a man from Helen's past returns into her life when he knocks on her door, reminding Helen that he knew her deceased mother and her many years ago, and that now he has come back for a most sinister reason... Interesting episode has a quite sophisticated idea at its heart, even if it is now rather obvious. Certainly a unique tale in the series canon, if not that well remembered.