The coincidences in this book are unbelievable, but at this point I'm so engaged in the story I'll just roll with it.
Chapter 6 - Triumph
During Darnay's trial, he, Gabelle, and his father-in-law testify that he had renounced his title and all its privileges. With the honor and love accorded Dr. Manette, this is enough to acquit him.
Chapter 7 - A Knock at the Door
Dr. Manette is proud of himself but Lucie is still terrified for her husband. It's too dangerous for them to leave France yet.
Once again Lucie hears foreboding footsteps. Charles is rearrested. Dr. Manette protests, but one of the arresting soldiers reminds him that he's expected to sacrifice for the Republic if need be.
Chapter 8 - A Hand at Cards
Out shopping for the celebratory dinner they don't realize has been abruptly canceled, Jerry Cruncher and Miss Pross stumble across her brother Solomon. Cruncher recognizes Solomon as one of the witnesses who accused Darnay in his trial for treason in England. Solomon advises his sister to hush because he's working as a spy for the Republic. Cruncher cannot recall Solomon's assumed name at the time of the trial. Out of nowhere, Sydney Carton appears and identifies it as Barsad.
Carton threatens the spy so, after returning Miss Pross to the Manette/Darnay home, Barsad accompanies them to Tellson's. Carton threatens to accuse Barsad of being an English spy if he fails to cooperate in Carton's plan. His evidence/card - he's seen Barsad with an English spy Roger Cly. Barsad counters by claiming that Cly is dead and buried. Cruncher speaks up and reveals that the coffin only contained rocks and other things to make it feel heavy. (That explains why he was so cranky and disappointed.)
Chapter 9 - The Game Made
Mr. Lorry admonishes Cruncher for his grave robbing. Cruncher does point out that he could have selfishly kept silent and, by the way, a bunch of doctors who employed him bank at Tellson's. He proposes that his son becomes the bank porter and he will become a grave digger to atone.
Carton and Lorry briefly talk about mortality and the fact that people will miss Mr. Lorry when he dies.
Carton wanders around Paris and buys some ether. He's coming to terms with the great sacrifice he's about to make.
After sunrise, he heads to the trial. The judge reveals that Darnay's accusers are the Defarges (no surprise) and Dr. Manette himself (gasps of shock and horror). M. Defarge reads a letter he found in 105 North during the taking of the Bastille. I completely missed that he left with something. Whoops.
Chapter 10 - The Substance of the Shadow
In his letter, Manette reveals that in 1757 the Marquis Evreémonde and his brother fetched him to care for a peasant woman, dying of a fever, and her brother, dying of a stab wound. The brother reveals that the marquis's brother raped his sister, killed his sister's husband, and stabbed him. He curses the family before he finally dies. The young woman, refusing to reveal her family name (I'm going to guess that it's Mme. Defarge's maiden name), dies a little later.
The Marquis's wife visits Dr. Manette in an attempt to atone for her husband's and her brother-in-law's actions for her son's sake. She knows that the late peasants had a younger sister who was hidden to protect her and she would like to help her. Dr. Manette doesn't even know the girl's family name. The Marquis (Darnay's father) ordered Manette to be imprisoned in the Bastille.
The jury sentences Darnay to death to pay for his father's and uncle's sins.