What does " the mission" refer to?

Context:

Blind Chinese activist Chen Guangcheng has pleaded for help to let him leave the country with his family, with a US-brokered deal for his future unravelling within hours of his leaving the Beijing embassy where he had taken shelter.

Chen said he never asked to leave China in his six days at the mission, which followed his incredible escape from a brutal 19-month regime of illegal house arrest. But he said he only left the embassy because US officials told him Chinese authorities would send his wife and children back to their home province – where they have been watched around the clock and harassed by a team of 100 guards – if he remained inside. He added that, at one point, an American official told him his wife would have been beaten to death – a claim denied by the US.

MOre:
http://www.guardian.co.uk/world/2012/may/02/chen-guangcheng-us-brokered-deal