Douglas Galbraith died without ever seeing his abducted sons. His sister is determined to find them

The first thing Douglas Galbraith noticed that warm night in 2003 when he arrived home from a work trip was that the curtains were open.

This was unusual. It was 10pm, and the two sons he shared with his Japanese wife Tomoko – six-year-old Satomi and four-year-old Makoto – should have been in bed.

With no key and no one answering the door, he took a screwdriver from the garage and forced his way in to the family home in rural Fife.

Inside he found a chilling scene. On the bedroom floor lay two small, crumpled pairs of pyjamas. Furniture, books and clothes were missing as well as photographs of the boys, a lock of Makoto’s infant hair and an ultrasound picture of Satomi before he was born.

On the doormat lay a single letter, from Royal Mail, confirming instructions for forwarding…