Million bad things coming from these factories (5)
I believe the answer is:
mills
'these factories' is the definition.
('mill' can be a synonym of 'factory')
'million bad things coming' is the wordplay.
'million' becomes 'm' (abbreviation).
'bad things coming' becomes 'ills' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'm'+'ills'='MILLS'
'from' is the link.
Can you help me to learn more?
(Other definitions for mills that I've seen before include "See 7" , "Bomb" , "Machines that grind or crush" , "Sir John - - (films)" , "factories" .)