Plot Twists in A Tale of Two Cities by Charles Dickens
The novel spans from 1775 and the outbreak of the American Revolution and its effects in London to 1793 and the height of the Reign of Terror of the French Revolution in Paris. As is typical of Dickens, there are a lot of characters. The main four are Sydney Carton, English lawyer and ne'er-do-well, Charles Darnay, a French noblemen who dislikes the actions of his class and lives in London and - it just so happens - looks just like Carton, Dr. Alexandre Mannette, just released from 18 years of unjust imprisonment in the Bastille, and Dr. Mannette's daughter Lucie, who helps him recover, later marries Darnay, and is the subject of Carton's unrequited love.
Of these main four, Carton and Dr. Mannette are interesting characters. Carton struggles with trying to make something of his wasted life, and with his affection for Lucie. Dr. Mannette and his return to himself is likewise an interesting character arc. Unfortunately, Darnay and Lucie are less compelling. Darnay is mostly just kind of "there" with no real highlight except for his confrontation with his evil uncle the Marquis, and an unfortunate lapse in judgement that leads him, a member of a noble family, to go to Paris in 1792. Lucie doesn't stand out much. She cares for her father and, later, daughter, and is the object of Carton and Darnay's affections. She doesn't really have much character of her own.
The secondary character are almost universally compelling. The Defarges, a winemaker and his wife in Paris, are leaders of the revolutionary patriots, with complex stories of their own. Madame Defarge, in particular, pretty much steals the scene whenever she shows up. Jarvis Lorry is a banker and friend of the main characters, and he's brave, savvy, loyal, and more world-wise than most. Jerry Cruncher and Miss Pross aid our heroes, and each have moments of brilliance. An unnamed seamstress appears late in the book and has more pathos in her short appearance than many books have between their two covers.
A Tale of Two Cities being Dickens, there are a ton of plot twists an unexpected revelations. Sometimes they seem to be a stretch, but, well, that's just how Dickens works, and pretty much every twist in fact is connected to a previous character or scene that comes back to be vital to the story. So, while it might be hard to believe that all these connections and surprises can fit into one story, Dickens makes them exciting and does a good job of justifying them in the buildup.
Dickens' language is fantastic. His description of the French Revolution and the Reign of Terror is particularly excellent. There are times he veers towards the wordy - though, by 19th century British standards, not especially so - but so often there are great lines, descriptions, phrases to be found in his prose that it's well worth it.