I am a big fan of this writer and have read many novel written by him. This one did not do it for me.
When you are not familiar with history between say 1900 and 1925 the book might be an interesting read as Colin sends his heroine to all mayor events in that timeframe: the poverty in Ireland and the resulting emigration, the sinking of the Titanic, the suffragettes, another sinking, the Russian revolution, gangster and bootleggers in the US etc. Thing is I know my history and that caused the feeling of impending doom and gloom while reading the book.
I had also problems identifying with Kitty. I am not a socialist so her enthusiasm for her causes was lost to me. Also as a result of the episode style of the book it reads more like a history book than a novel that sucks you into a situation.