The staff to work wonders? (4)
I believe the answer is:
wand
'the staff' is the definition.
(wand is a kind of staff)
'work wonders?' is the wordplay.
'work' becomes 'w' (physics abbreviation).
'wonders?' becomes 'and' (I can't justify this - if you can you should give a lot more credence to this answer).
'w'+'and'='WAND'
'to' is the link.
Can you help me to learn more?
(Other definitions for wand that I've seen before include "Wizard's rod" , "Extremely angry" , "Magician's rod" , "Fairy's stick" , "Magician's accessory" .)