Stealthily pursued, son spoke (7)
I believe the answer is:
'stealthily pursued' is the definition.
'stalked' can be an answer for 'pursued' (stalking is a kind of pursuing). I am unsure of the 'stealthily' bit.
'son spoke' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'spoke' becomes 'talked' ('talk' can be a synonym of 'speak').
Can you help me to learn more?
(Other definitions for stalked that I've seen before include "Tracked stealthily, game or victim" , "Pursued (someone) to an obsessive degree" .)