On the south bank of the river, in addition to the town of Huashen in the west, there is a large residential area in the east, with more than 2,000 households. A cross street divides the inhabitants into four sections.

This place has a very interesting name: "Thirteen Battalions". It is said that there were troops stationed here during the Three Kingdoms period.

In the "Thirteen Camps", there is an old theater with a long history, and its location is at the crossroads, which existed during the Ming Dynasty.

There is also a nunnery in the "Thirteen Battalions", and the three-storey old-fashioned building on the other side of the river that we mentioned earlier, Zhu Laosan as a reference for the fish nest, is part of the nunnery, and the name of the nunnery is "Ma Po Po Nunnery". Throughout the ages, it is rare to build a temple in the downtown area, in Jingnan City, there is a relatively large nunnery, which is also built in a densely populated place, it is "Jiming Temple".

To the west of "Ma Po-an", there is also a pickle factory, and if you pay a little attention, you will smell the pickles in the air. This very special smell has been smelled by the residents living on both sides of the river for many years. Of course, they have also listened to the ancient and quiet bell of "Ma Po Po An" for many years.

The back door of the "Ma Po Po Nunnery" and the pickle factory is open on the river embankment. Two stone stairs that wind down to the river, and on the pier of the pickle factory, a relatively large wooden boat is docked.

Zhu Laosan said that in addition to transporting goods, the wooden boat of the pickle factory is usually locked to a large willow tree on the shore with iron chains. When he fishes on this side of the river, he can often see children playing on wooden boats, and occasionally anglers will sit on wooden boats and fish.

Ouyang Ping and Chen Jie's visit to the "13th Battalion" took a long time, and the location of the crime was on the Qinhuai River, and the specific location was on the north bank, but the 13th Battalion, which is separated by a river, should also be considered as the environment in which the case occurred.

As we all know, Ouyang Ping has been engaged in criminal investigation work for more than 20 years, and in the process of handling cases, he has always attached importance to the study of the environment and background, and any case is inseparable from the environment and background. The strangeness of the case is inextricably linked to the complexity of the background and environment. When the murderer commits the crime, he will also take into account the environmental factors. Hiding the body of the deceased about five meters away from the north shore and two meters under the water, two city wall bricks fell on the deceased's body, and the deceased's head was cut off and hidden elsewhere, all taking into account the environmental factors, so Ouyang Ping hoped to interpret some valuable information from the environment of the crime scene.

In the "Thirteen Battalions", Liuyedu and Moling Road, there are a total of four hardware stores ("Thirteen Battalions" have one, Liuyedu has one, and Moling Road has two), Chen Jie and Li Wenhua took the thin iron wire used to bind the corpse and the city wall bricks, and went to the four hardware stores to investigate and visit, this type of iron wire, four hardware stores have, according to the total length of the wire, such a long iron wire, must have been bought in the hardware store, this kind of iron wire is sold in catties, the comrades wrapped all the iron wires together, weighed them with electronic scales, The total weight is 1.69 kilograms, and when the murderer bought the wire, it should be about two kilograms, but unfortunately, the owners of the four hardware stores had no impression of the customers who bought the wire, they said that half of the people who bought this kind of wire were units, and the unit was a large bundle (the weight of a bundle of wire was five kilograms).