Inspector Troy back in force beginning to show intelligence (7)
I believe the answer is:
tidings
'intelligence' is the definition.
(I know that intelligence can be written as tidings)
'inspector troy back in force beginning to show' is the wordplay.
'inspector' becomes 'di' (abbreviation for Detective Inspector).
'troy' becomes 't' (abbreviation - troy is a unit of weight).
'back' shows that the letters should be reversed in order.
'force' becomes 'g' (short for gravity).
'beginning to' suggests taking the first letters.
The initial letter of 'show' is 's'.
'di'+'t'='dit'
'dit' back-to-front is 'tid'.
'tid'+'in'+'g'+'s'='TIDINGS'
(Other definitions for tidings that I've seen before include "Information about recent events" , "News, reports" , "News (obs.)" , "News, information" , "News (arch.)" .)