Who killed Wu Hongda in The Rainbow Catcher?

The housekeeper found the address of Shu's lover. When Jiang Yu was away, the housekeeper gave the address to Fang Feifei. Jiang Yu and Rainbow walked downstairs side by side, which made Fang Feifei jealous. After Jiang Yu got the address, he asked Rainbow to go with him to find Shu's lover. But when they arrived, they found Shu's lover had already been killed on the sofa. Rainbow thought Jiang Yu had a plan, deliberately pulled himself up and gave him circumstantial evidence. He even decided that Jiang Yu was the murderer of his father.

While they were arguing, Zhou Shaotian came and took the rainbow away. The forensic doctor found metal fragments of Parker's nib in Wu Hongda's body. Rainbow said Jiang Yu had such a pen. The detective thought that if Jiang Yu killed someone, it would be impossible to leave the nib in his body.

Every time someone cuts off all the clues in front of Jiang Yu, Jiang Yu concludes that this person is by his side. Today, Zhou Shaotian suddenly appeared at the scene of the murder. He began to doubt Zhou Shaotian. Fang Feifei told Jiang Yu that he told Zhou Shaotian the address of Shu's lover's home. Jiang Yu just dispelled his doubts about Zhou Shaotian.

Zhou Shaotian came to Sigh's hiding place. Shu admitted that he killed his mistress. He asked Zhou Shaotian to help him leave Huzhou quickly. He and Zhou Shaotian are in the same boat. If something happens to him, Zhou Shaotian can't get away with it. Zhou Shaotian resented Shu's threat to himself. Shu's wife rushed out and knelt down to ask Zhou Shaotian to help them. Zhou Shaotian promised to help Lao Cai find a way to leave Huzhou as soon as possible.

Rainbow went to the hospital to take care of Zhou's mother. When she left, she met Mrs. Jiang in the corridor. Mrs. Jiang wants to read the newspaper. She asked Rainbow to go home and bring her glasses. Rainbow came to Fu Jiang to find a chance to sneak into Jiang Yu's room and took Parker's pen. He happened to meet Jiang Yu when he went out. Rainbow made up an excuse and left in a hurry

Jiang Yu felt something was wrong. When he returned to his room, he found that the pen was really gone. Rainbow gave Jiang Yu's pen to the inspector. The model of the pen is exactly the same as the fragments on the body. The detective asked his men to take Jiang Yu to the police station. Jiang Yu admitted that the pen was his own, but the nib was intact. Why are there fragments in the body? The inspector ignored this detail and there was no other conclusive evidence to release Jiang Yu.

The next day, Rainbow came to work in Linglong as usual. Fang Feifei accused Rainbow of being too thick-skinned. She doesn't allow the rainbow to stay in Linglong. Jiang Yu told her sister that she had other plans to leave the rainbow in Linglong and told her not to get involved between herself and the rainbow. Fang Feifei reminded Jiang Yu not to be fascinated by the rainbow and told him not to forget his father's hatred.