Now Mao needed aid, and the Soviet Union with which he already enjoyed good relations was the only possible source. The Russians had got their client China, but not the kind that they would really have liked. It was two and a half months after his triumph that Mao set off for Moscow (and it is observable that he travelled by train, not risking the contrivance of a plane 'accident' by Stalin). The bargaining between the two historic figures took two whole months (although much of it was delegated to secondary men), for Mao alighted in Moscow on 16 December and the first three of the group of treaties and agreements were not signed until 14 February. Remarkably little is still known of what happened in this time.