How does the author lead up to Sydney Carton's sacrifice in A Tale of Two Cities?A Tale of Two Cities by Charles Dickens

In A Tale of Two Cities by Charles
Dickens, there are several instances of foreshadowing in which the author provides hints
for the sacrifice of Sydney Carton:

• During the
  trial of Darnay, Carton observes Lucie Manette and is immediately smitten by Lucie, whom
  he alludes to as "the golden-haired doll." His love for Lucie later leads him to declare
  to her that he will do anything to help her in the
  future.


• When he takes Charles Darnay out for a meal at
  the tavern, Carton congratulates him on his acquittal and even broaches the subject of
  Lucie as "a fair young lady to be pitied by and wept for by," indicating his envy of
  Darnay.  But, it is not just envy that Carton feels for his double; in Darnay he sees
  what he could have been, an observation that is key to his future
  sacrifice.


• That Sydney Carton senses the eventual
  revolution is indicated in Chapter 6 of Book the Second in which he tells Lucie, "There
  is a great crowd coming one day into our lives, if that be
  so...."


• In Chapter 13 of Book the Second, Carton speaks
  to Lucie and notes that he has "unformed ideas of striving afresh, beginning anew,
  shking off sloth and sensuality, and out the abandoned dream....you inspired
  it."


• Most significantly, in this chapter, Sydney pledges
  to Lucie, "For you, and for any dear to you, I would do anything.  If my career wer of
  that better kind that there was any oppotunity or capacity of sacrifice in it, I would
  embrace any sacrifice for you and for those dear to
  you."


• When he learns that Charles Darhay is endangered as
  an aristocrat in France, Carton travels to Paris to assist in any way he can.  During
  his investigations, he learns from Jerry Cruncher information on Barsad, who works at
  the prison where Darnay is held. This knowledge helps Carton form his plan for saving
  Darnay.


• In Chapter 9 of Book the Third, after Carton
  leaves the chemist where he has purchased certain packets to effect his plan, he walks
  the streets, recalling the solemn words read at his father's grave, "I am the
  resurrection and the life...he that believeth in me, though he were dead, yet shall he
  live...."  These words from the New Testament give rise again to the theme of
  resurrection as Carton contemplates that he can redeem himself in
  death.