Tinker Tailor Soldier - and sure ultimately apt to include - Spy (6)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Tinker Tailor Soldier – and sure, ultimately apt to include Spy M (=spy, in James Bond films) in *(<soldie> R + <sur> E + APT); “ultimately” means last letters only are used in anagram, indicated by “tailor”