Pledge of the twin blades (part 1) (1962)

Lau Ching-yee sets out to investigate the raid on her uncle's consignment of silver when she stumbles upon two suspects, the stately Cheung Ting-yu and his attendant Mang Leung. Cheung makes the acquaintance of the knight-errant Poon Mo, who is recruiting allies to join the band of martial adepts against Tsak Sing-tau in the ring to win 20 chests of jewels for the poor. Failing to pressure Cheung to turn over the silver, Lau engages him in a fierce fight until the respected elder Moh Oh-ming intercepts and settles the dispute. Who is behind these strange events?