Return to Pontarfynach: The past comes back to haunt DCI Mathias as he investigates the death of Catrin John, convicted killer and former resident of the Pontarfynach Children's Home. Mathias and Mared see a link between the case and the death of Iwan Thomas. But John Powell is on the cusp of ruling Iwan's death a suicide. With mounting pressure to close the case, will Mathias toe the line or risk it all for the truth?