Treachery at the top? (4,7)
I believe the answer is:
high treason
'treachery at the top?' is the definition.
I can't tell whether this defines the answer.
'treachery at the top?' is the wordplay.
I cannot quite see how this works, but
'treachery' could be 'treason' (synonyms) and 'treason' is found in the answer.
'top?' could be 'high' (associated in meaning) and 'high' is present in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for high treason that I've seen before include "Betrayal of one's country" , "crime against the state?" , "Capital offence" .)