 The two days before Gu arrived in Nanjing to meet with Chiang gave Zhou time to evacuate Party members and to change the communication codes used by "Teke", all of which were known to Gu.After meeting briefly with Chiang in Nanjing, Gu arrived in Shanghai and assisted the KMT secret police in raiding CCP offices and residences, capturing members who could not be evacuated in time.The summary executions of those suspected of Communist sympathies resulted in the largest death-toll since the Shanghai massacre of 1927.