Munich wolf by Rory Clements

When a high-born English girl is murdered, Wolff is ordered to solve the crime. He has a fine record and, importantly, he is fluent in English. But he realises the mission is a poison chalice, for Hitler is taking a personal interest in the case – as is his young English acolyte Miss Unity Mitford. Wolff is hemmed in on all sides. At work, he is watched closely by the secret police, at home he could be denounced at any moment by his own son, a fervent member of the Hitler Youth. And when he begins to suspect that the killer might be linked to the highest reaches of the Nazi hierarchy, he fears his task is simply impossible – and that he will become the killer’s next victim.