Meanwhile, Cao Qin began to suspect that the plot was leaked, and so moved with his troops around 5:00 to 7:00 AM on August 7 to inspect the gates of the Imperial City; when the Dongan Gate (the eastern entrance) failed to open, his suspicions were confirmed.
Sementara itu, Cao Qin mulai mencurigai bahwa rencananya bocor dan bergerak bersama pasukannya antara pukul 5.00 hingga 7:00 pagi tanggal 7 Agustus untuk mengamati gerbang Kota Imperial; saat Gerbang Dongan (pintu masuk dari timur) gagal terbuka, kecurigaannya terbukti.