And there were in the city, a gang of nine (persons) who had upset the stability and peace in the country and would not reform (themselves). (Quran, Sūrah al-Naḥl (27), Verse 48)
Commentary
NUMBER 9: This verse speaks about the event which transpired during the time of Prophet Ṣāliḥ with respect to his community and the plots of his people, including that of the plan of the disbelievers and hypocrites to assassinate him. 
History tells us that in his city, Wādī al-Qurām, there were nine groups who were busy spreading corruption on the earth – destroying the balance of peace and societal order. Although they were a small group of people, each of them had their own corrupt ways and were working towards one goal – societal corruption. They sought to corrupt the beliefs and pollute the morality of the communities which they resided in.
The fact that Allah uses the phrase ‘و لا يصلحون’ shows us that this is something that they were intentionally doing. Sometimes, a person may commit a sin or perform some act of mischief in the society, but they feel remorse and try to mend their ways; however those who actually sow the seeds of corruption never feel remorse for their actions and definitely do not want to reform themselves or humanity.
In this verse, we also see that Allah uses the present tense verb by saying ‘يفسدون’ and this points to the fact that they were engaged in this wicked behaviour on a continuous basis.
The story continues in the verses which follow, but to summarize, they ended up planning to carry out their nefarious deeds and even did so by taking the name of God! This is something that we see even today when the terrorists – whatever religion they profess – who carry out their evil actions, and use the name of God to justify their actions – but the fruit does not fall far from the tree! 
Eventually they tried to assassinate Prophet Ṣāliḥ @, however Allah blocked their evil plans and rather than him and his family being killed in the darkness of the night, the tables were turned and the enemies of Allah ended up being crushed to death by large boulders. Allah says in the Quran in several places: “People plan and Allah too plans,” and as we know, “Allah’s plans are always the ones which reach to fruition because He is the BEST of planners!”
Point of Reflection 
We must realize that corruption is all around us and sometimes, those who spread the seeds of evil may claim to be within the fold of the teachings of a certain faith, however they NEVER reflect the truth of the message. Allah may give some people respite, but eventually their evil fate will catch up to them.