In the finale of The Undoing, Jonathan, Grace’s partner, is brought to justice, but the series does not address some interesting questions raised throughout the show.
Did Jonathan kill his sister?
The circumstances surrounding Katie’s death are vague in The Undoing. Instead of babysitting his sister, Jonathan allows Katie to leave the house and into oncoming traffic.
Jonathan takes Elena’s life so easily, that even for a doctor who deals with life and death every day, he doesn’t seem affected. As if, perhaps, it was not the first time in The Undoing.
Henry is a sociopath?
The Undoing foreshadows the possibility of Henry being the killer when he confesses to Grace that he saw Jonathan with Elena. When Grace finds the murder weapon in her violin case, Jonathan’s suspicions that his son murdered Elena mimic what onlookers think.
This plot twist in The Undoing forces the audience to rethink everything Henry has done and how he has reacted to situations up to that crucial moment (even more so in a second viewing).
He knows his father is guilty, but he still pushes them to reconcile. Henry lies manipulate evidence with a dexterity that should allude to someone so young and is one step ahead of his mother for most of The Undoing.