Strike first hears of Ben Liddell from Jade Semple in Crieff. She tells him that her husband Niall’s ‘best friend in the Regiment, Ben, got killed same time Niall got injured’ (Ch 59).
Later, Strike meets up with his old RMP friend, Graham Hardacre. Hardacre tells Strike that Semple was very angry about Ben’s death, and that he’d heard the operation was ‘botched’.
Strike later finds out that Ben, like Semple, was Scottish and also that he had a sister called Rena (Ch 73).
Strike meets with Rena later in the book. She is able to provide some further useful information about Niall Semple.