It could have been a better film. It does drag at points, and the central story shifts from Boyer completing his mission to Boyer avenging Wanda Hendrix's death, but Graham Greene is an author who is really hard to spoil. His stories are all morality tales, due to his own considerations of Catholicism, guilt and innocence (very relative terms in his world view), and the human condition.
Boyer is Luis Denard, a well-known concert pianist, who has sided with the Republicans in the Spanish Civil War. He has been sent to England to try to carry through an arms purchase deal that is desperately needed. Unfortunately for Denard he is literally on his own - everyone of his contacts turns out to be a willing turncoat for the Falagists of Spain. In particular Katina Paxinou (Mrs. Melendez) a grim boarding house keeper, and Peter Lorre (Mr. Contreras) a teacher of an "esperanto" type international language. Wanda Hendrix is the drudge of a girl (Else) who works for Mrs. Melendez. The local diplomat, Licata (Victor Francken) is already a willing associate of the Falangists.
The Brits (Holmes Herbert, Miles Mander, and best - if not worst - of the lot, George Coulouris) don't give much hope to Boyer's cause (which he soon grasps may be Britain's before long). Herbert and Mander just retreat behind the official policy of neutrality ordered by the Ramsay MacDonald's and Stanley Baldwin's governments during the Civil War. Coulouris here is a typical Col. Blimp type - always impeccable in his native English diction, he is sharp in showing his dislike for foreigners in general.
The one ray of hope is Lauren Bacall (Rose Cullen), here trying to play her role as well as she can - but she can't really. She's an aristocrat - the daughter of a Press lord. It was Bacall's second film, and (sad to say) almost sank her long career. She does act well, but the spark she showed in her first film was due to the dual effect of starring with Humphrey Bogart and being directed by Howard Hawks. Boyer is a fine actor, but he's not Bogie, and Herman Shumlin is not Hawks. Her next film returned her to Bogie and Hawks again, and her star resumed it's ascendancy.
It's a bleak film (as was the novel). Boyer's mission never succeeds, as he has too many hidden foes all over the place. But the villains are likewise also losers - frequently with their lives.
With Dan Seymour as a suspicious foreign tenant of Katina Paxinou (and the man who destroys her). It is well worth watching to catch the Warner's lot of character actors doing their best given the weakness in direction.

OK the director remakes LOVE ACTUALLY The director Nikhil Advani after debuting with KHNH does his second half and wait
He makes a 3:30 hours + film which loses on patience, time.etc The viewer seems like a 3 hrs sleep watching this film
OK they had 6 stories so it was necessary but why? 6 stories?
We have the Anil- Juhi story convincing but boring don't TV serials show such stories?
We have Govinda- Shannon story which is funny and works well
We have Akshaye-Ayesha story again believable but gets boring soon and the focus is on comedy more and that too slapstick boring comedy
We have Salman- Priyanka story which is the worst, not just acting terms, it makes no sense at all
We have Sohail- Isha story to make you laugh and the trick works at times thanks to the boredom set by most of other stories
We have John- Vidya story a good story in all respects
But then by the time all stories come in bits n pieces the viewer gets bored and sleepy The climax isn't appealing though especially The climax of Salman- Priyanka story Nikhil Advani's handling is alright at places, some stories are well handled but weak at places Music(SEL)is good, but too many songs Cinematography is nice, every story is given a different look, texture and it works
Actors Govinda rocks, after a dismissal comeback with BB he actually makes you laugh and love him in this film despite his age and weight Anil Kapoor acts his part well, though he looks out of shape and tired John excels in his part, Akshaye Khanna overacts for a change
Sohail Khan is too over- the - top and Isha has nothing to do Anjana Suknani is dismissal
Priyanka and Salman deserve an award for this film you are shocked?
Salman Khan doesn't act only, just talks like he is in his sleep and that fake accent oh god Priyanka overacts to such a standard you feel like throwing something on her, she does get better towards the end Vidya Balan is good, Juhi Chawla is okay Shannon is okay