Ursula Todd is an Englishwoman born in 1910 who experiences time as a looping cycle.
The book follows a myriad of possible alternatives for Ursula's life path, one after the next. Small changes lead to different outcomes and as they progress Ursula starts to experience strange sensations of deja vu, as the memories of past lives seep through to the next.
At the very beginning of the book we see an adult Ursula walk into a bar and shoot Hitler.
Next we see as Ursula is born during an ice storm, and lives just a few minutes due to the late arrival of the doctor. Next we see a version where the doctor left before the storm and arrives in time to save her, this time she dies as a young child due to the flu, and the next time from falling from a window. As each timeline ends with her death we move to the next, with different choices leading to longer lifetimes.
Her mother has another child, or two more. Ursula's childhood friend Nancy is murdered by a vagrant, or in the next timeline Ursula runs into her on the walk home and that fate is avoided, Nancy marries Ursula's younger brother instead. Ursula is assaulted by her elder brother's friend on her sixteenth birthday and dies from the subsequent illegal abortion, next time she survives but ends up moving to London and marrying an abusive man who kills her in a fit of jealousy. The time after that the teenage assault never takes place and Ursula travels to Germany instead of London, marrying a German and dying in the Allied bombing of Berlin.
Each time we see the various places where a decision or interaction change the next portion of her life. At first Ursula doesn't quite remember the previous timelines, but as it goes on more memories come through. An image of her crib as a baby, and sudden premonitions of impending tragedies. Eight year old Ursula pushes the maid down the stairs to prevent her going on a trip that will result in her coming home infected with the flu. This causes her parents to send her to a psychiatrist for a while, where Ursula learns a bit about reincarnation, but mostly about discretion.
Ursula grows up and experiences World War II and the blitz. She works as in the War Office and has an affair with a married Navy man, or with a young architect, or in other timelines with both of them or neither. She volunteers for the rescue brigades that dig up the casualties during the bombings, and she dies in a building collapse, then a gas leak, then crushed by a wall.
In several iterations she travels through Germany before the war, and in one of them she ends up living there and briefly staying at the Berghoff, Hitler's mountain retreat. She meets the führer and fantasizes about killing him and ending the war. These memories faintly seep into later lives when she is in London during the blitz.
As the book progresses she starts living her lives consciously trying to mold the outcome, central points like the maid's influenza infection and her friend Nancy's death become points at which she attempts to change the future. The results are not always successful but she perseveres and even chooses death when she fails to avoid Nancy's murder.
Towards the end we see her with the most clarity that she has experienced so far, she concocts a plan for her next life that she believes will change things utterly, she decides she will learn German and shoot Hitler before the war. We see the scene from the beginning of the book play out, Ursula shots him and is killed herself by his companions. Next we see her being born once more.
Best part of story, including ending:
A great deal of the book is spent with Ursula's family, and they're very vividly drawn; her doting father, slightly detached mother, insufferable older brother, giddy aunt Izzy, beloved younger brother Teddy. Their personalities are a stable core to the changing story.
Best scene in story:
I loved any interactions that included Aunt Izzie, who is the black sheep of the family. But particularly there is an extremely uncomfortable dinner when almost everyone is present for a change and every interaction is fraught with family resentments, secrets, and rivalries. It's squirm inducing but hilarious.
Opinion about the main character:
Ursula is quite funny in a quiet way, and very philosophical and practical even before she realizes her situation. You can't help but admire her even when she makes the wrong choices.