Chinese Whispers by Jan Wong

Chinese Whispers Searching for Forgiveness in Beijing
by Jan Wong
ISBN 13: 9781843549741 | ISBN 10: 184354974

Here's the blurb:

In 1972, Jan Wong became one of only two Westerners admitted to Beijing University at the height of the Cultural Revolution.
One day a student, Yin Luoyi, sought Jan's assistance in going to the United States. Wong, then a starry-eyed Maoist from Montreal, was that most dangerous combination in the young - ignorant, innocent and idealistic - and she reported Yin to the authorities. Wong knew nothing of what ensued. Indeed, she completely forgot about her brief encounter with the young stranger until many years later.

Now, thirty-three years on, Wong returns to Beijing to search for the woman who has haunted her conscience. She hopes to apologise, perhaps somehow to make ammends. At the very least, she wants to find out whether Yin has survived.
Preoccupied by the past, fascinated by China's present and future, Jan Wong searches out old friends, foes and comrades in this half-familiar city, finally uncovering the truth about the woman she wronged.

Chinese Whispers tells a unique and unforgettable story of communism and capitalism, of guilt and attonement, of remembering and forgetting.

Here's a review