On the 14th of May 2018, Ana Kriégel left her home in Leixlip, Co Kildare, with a promise to her father that she wouldn't be long. 

But Ana never came home and her disappearance sparked a three-day search of a local park, the last place where she had been seen walking with another child.

It was a missing person's case that gripped the nation as everyone hoped the smiling girl in her favourite black hoodie would be found.  What happened would  become one of Ireland's most disturbing and unsettling cases.

In this episode of Lines of Enquiry, John Sweetman takes us back to those dark days of her disappearance, and why her killers will never be named.

Presented by John Sweetman

Created by Darren Cleary

Episode Written by Siobhán Maguire and Eoin Brennan

Script Edited by Eoin Brennan

Produced by Siobhan Walsh

Produced by Siobhan Maguire

Executive Produced by Eoin Brennan

Executive Produced by Ruth Fitzsimons

Sound Design and Editing by Neil Kavanagh

Audio Editing Support by Ed Smith

Marketing Support by Laura Bracken and Róisín Reilly

Social Support by Mark Hayes and Robyn Ree

Artwork and Graphics by Eric Rowntree