Come to grips with story about heartless crook (6)
I believe the answer is:
tackle
'come to grips with' is the definition.
(tackling is a kind of coming to grips with)
'story about heartless crook' is the wordplay.
'story' becomes 'tale' ('tale' can be a synonym of 'story').
'about' indicates putting letters inside.
'heartless' suggests removing the centre.
'crook' with its centre removed is 'ck'.
'tale' placed around 'ck' is 'TACKLE'.
(Other definitions for tackle that I've seen before include "Undertake" , "Deal with; equipment" , "block" , "Try - made by a rugby player?" , "Try to deal with, rugby opponent or problem" .)