He's broken and wants revenge for Vesper. So much so he and the Bond Girl out for her own revenge never even have sex. You really should know who Vesper is for this to land. Plus, the movie is rather short and low on plotting (owing to the writer's strike) as it is. It works much better if watched soon after Casino Royale than it does on its own.
Because of the reaction to OHMSS and its lack of Connery, they weren't really sure on if they were treating it like continuity and you can tell. The way Bond banters back and forth with Bloefeld later in the movie doesn't seem at all indicative how he would act with the man who murdered the love of his life.Again, to draw a comparison to an older Bond, here it's Diamonds are Forever. DaF opens with Bond hunting Blofeld. The movie never explicitly tells you why, and it doesn't really matter.
The comparison to Quantum doesn't work at all. Not only is Vesper and the scheme the villains used to turn her specifically talked about, but Mathis shows up and his recent history with Bond also matters. And of course, the movie picks up just hours or perhaps even minutes right after the final scene of CR.
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