I say it was the worst of books not to be unduly harsh on A Tale of Two Cities but because, of the handful of Dickens's books I have read, this is probably my least favorite. Dickens is by no means my least favorite author though, so the criticism could be taken as a complement.
My chief complaint is the lack of characteristic humor. Even in a book as depressing as Hard Times,there was always plenty of comic figures to laugh over as the pages turned. Not so in A Tale of Two Cities, here the only mildly funny people are Mr. Cruncher and Miss Pross. Sidney Carton starts out as a buffoon but ends the book as the most tragic figure, heroically laying down his life for his friends. I think I went into the book with the wrong preconceived idea of what it would be like. The stormy gloom of the first chapter should have told me that this book was deadly serious.
The two cities are London and Paris. The time is during the French Revolution. If you wish to know why a happily married Charles Darnay leaves the safety of England and travels to Paris, or how he is imprisoned there, and what his friends do to rescue him from the guillotine, you will have to read it yourself.
I take the two main themes to be forgiveness and friendship. By friendship I mean those qualities of loyalty, sacrifice, and care that a friend (or lover) has for another. The reconciliation between Dr. Manette and his daughter's husband is contrasted with the merciless hatred of Madame Defarge. Though they both have been wronged, Manette does all he can to help Darnay as a true friend. He is in the end powerless to save Darnay from the hate of Defarge. Only a greater love can overcome this great hate, and Carton, in the moment of despair, supplies this.
Dickens dwells long on the anarchy and blood of the Revolution of the French people, yet his sympathy is with those people. The oppression and tyranny they suffered under, he says, "produced this horror."
Crush humanity out of shape once more, under similiar hammers, and it will twist itself into the same tortured forms. Sow the seeds of rapacious license over again, and it will surely yield the same fruit according to its kind.