Una Lynskey was 19 years old in October 1971, and she had a job with the Land Commission in Dublin City.

On the evening of Tuesday 12th October, she stepped off a bus on the Fairyhouse Road near Ratoath, Co Meath when she hurried up Porterstown Lane towards her family's farm, a walk that would take no more than 15 minutes.

She never made it home.

A search began within the hour, but there was no sign of her.

However, soon there were repeated descriptions of an unusual car on the lane that afternoon, and a number of locals in the area remembered hearing screams not long after Una got off the bus.

Who would have taken her? And why?