Back one who misled editor and wreck plans (6)
I believe the answer is:
derail
'wreck plans' is the definition.
'derail' can be an answer for 'wreck' (I've seen this in another clue). I'm not certain of the 'plans' bit.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for derail that I've seen before include "create an obstructive diversion" , "go off line" , "Force off track, like a train" , "Of train, force off tracks" , "Cause to come off the tracks" .)