One getting fires going so trains will move (8)
I believe the answer is:
arsonist
'one getting fires going' is the definition.
(someone who starts fires)
'so trains will move' is the wordplay.
'will move' is an anagram indicator.
'so'+'trains'='sotrains'
'sotrains' with letters rearranged gives 'ARSONIST'.
(Other definitions for arsonist that I've seen before include "A major criminal" , "One firing property" , "Like blazes he will" , "So strain (anag.)" , "Incendiary, firebug" .)