Why don't we return from the wastelands! (4)
I believe the answer is:
lets
'why don't we' is the definition.
(I've seen this in another clue)
'return from the wastelands' is the wordplay.
'return' says the letters should be written in reverse.
'from' says the answer is hidden in the clue.
'stel' is hidden within 'wastelands'.
'stel' in reverse letter order is 'LETS'.
(Other definitions for lets that I've seen before include "Rents out or allows" , "Permits" , "we shall serve them again!" , "Yes" , "Leases" .)