5.38 emphasizing time and duration

If you want to emphasize the recentness and the duration of a continuous activity which took place before a particular time in the past, you use the past perfect continuous.

• Until now the rumours that had been circulating were exaggerated versions of the truth.
• The doctor had been working alone.
• He arrived back in Munich from Rome where he had been meeting other OAS leaders.
• They had been hitting our trucks regularly.