Recently, Barry Stevens found out that he may have as many as 100 to 200 half brothers and sisters. Stevens and his mystery siblings were among the first artificially conceived humans – the offspring of an anonymous sperm donor who lived in England half a century ago. Now, Stevens is searching for the identity of the shadowy figure from whose loins they all sprang. His film – essentially a detective story set in the brave new world of reproductive technology – also questions the meaning of family and blood ties.