Hunt traitor with likely winner outside kept apart (12)

'kept apart' is the definition.
('sequestrate' can be a synonym of 'keep apart')

'hunt traitor with likely winner outside' is the wordplay.
I cannot really see how this works, but
'hunt' could be 'quest' (synonyms) and 'quest' is located in the answer.
'traitor' could be 'rat' (rat can mean a treacherous person) and 'rat' is found within the answer.
The remaining letters 'seed' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?