The past comes back to haunt DCI Mathias as he investigates the death of Catrin John, a convicted killer and former resident of the Pontarfynach Children’s Home. As the investigation proceeds, Mathias and Mared begin to suspect it might be linked to the death of former police officer Iwan Thomas. However, independent investigator John Powell is on the cusp of ruling Iwan’s death as a suicide – could this change things?