Behind that curtain by Earl Derr Biggers

Nice, not bad indeed. A detective novel written in 1928 with protagonist sergeant Charlie Chan of Honolulu. He's in San Francisco on holiday where he is introduced to Sir Frederic Bruce, a great man retired from Scotland Yard. Their meeting is organized by journalist Bill Rankin, hoping for a nice story, and although he's banned from writing a single word at the moment, he'll be rewarded at the end with an exclusive on the murderer. Other characters are Barry Kirk, a wealthy young man who hosts sir Frederick and later Charlie Chan. Miss J. (June) V. Morrow, working in the district attorney's office. Captain Tom Flannery, in charge of the investigation, an unpleasant man all barking and zero deductions.
Sir Frederic talks about an old case, the murder of a man called Hilary Galt, and also about the case of Eve Durant that years ago vanished leaving no trace. He still hasn't give up on those cases, but during a dinner he's killed in Kirk's office. Chan should leave to go back home where his eleventh child has been born but at the last moment he stays to follow the investigation. At the end  - Spoilers!!! you, and I, have been warned...
he solves the case, although the glory will go to captain Flannery. He finds Eve Durand to be the real identity of the girl working at the lift in Kirk's building. Many years ago she had realized the man she had married was a murderer, he had killed Mr Galt, so she plans to escape. She's helped by colonel Beetham, an adventurer, to go from India to Teheran, where she leaves him. She changes identity, and  keeps changing it every time sir Frederic gets too close. Her husband Eric Durand kills sir Frederic knowing that he would have never stopped his search for Galt's murderer. As soon as the case was solved, Chan left and went into hiding for a few days, until the moment to board a ship for Honolulu, so to avoid any other cases :-lol
He's determined to go home this time, he misses it very much.
I was a bit annoyed at his views on women , but after all it's 1928 and he was always very respectful, so it's ok.
Kirk and Miss Morrow's love story was so predictable it doesn't count. In the complex a nice crime novel, I wouldn't mind to read more Charlie Chan's stories :-)

Ita:Charlie Chan e la donna inesistente