When Paul Caruana Galizia was at work in London, his eldest brother called to say their mother Daphne an acclaimed journalist had just been assassinated. That day, he returned to their native Malta and, with his two brothers and their father, began a quest to discover who was responsible for Daphne's murder and who stood to profit from ending the life of a journalist whose courage and determination threatened the powerful with the truth. He speaks to Anne Applebaum about the family's quest for justice.