Barrister Martin Ainsworth is sent to West Berlin by British Intelligence to make contact with his former lover, a suspected Communist agent, and it's up to him to find out the truth and to spot her contacts.

As he travels through a divided Berlin, his dual role becomes emotionally tortuous, his lack of training an unforeseen hazard, and he turns more reckless than his peers had ever bargained for ...

'A more or less conventional spy story is suddenly turned inside out by a most ingenious twist' Guardian