Evil doctor following with attention? Forget it (2,4)
I believe the answer is:
no fear
'forget it' is the definition.
(both can be emphatic denials)
'evil doctor following with attention?' is the wordplay.
'evil doctor' becomes 'No' (Dr No, James Bond villain).
'following' becomes 'f.' (used when citing page numbers etc).
'with' is a charade indicator (letters next to each other).
'attention?' becomes 'ear' (having someone's ear is having their attention).
'no'+'f'+'ear'='NO FEAR'
(Other definitions for no fear that I've seen before include "Absolutely not" , "What 7 [INTREPID] person will have" , "what the bold show" , "Informally, certainly not., who's afraid" , "Definitely not (sl.)" .)