W. W. Norton & Company; 7/26/16
eBook review copy; 464 pages
Ada Sibelius is 12 when she first learns about her father's early-onset Alzheimer's. As an only child of a single father, David Sibelius has been Ada's whole world. Daily he brought her to his computer science lab on the campus of a prestigious university in Boston. She was home schooled, His lab colleagues are her friends. They have been working on an A.I. program they call ELIXIR. Ada herself talks to ELIXIR to help the program learn human speech.
Diane Liston, one of David's colleagues, as well as a friend and neighbor, knows something is wrong and encourages David to tell Ada, especially when David disappears for over a day without a word to Ada. As David's condition worsens, Ada attends a public school for the first time while trying to hide from others how bad David's condition has deteriorated. It soon becomes evident that David must be sent to a care facility and Ada will be cared for by Liston.
It is once she is living with Liston as her legal guardian that Ada learns that her father may not be who he said he was. The search is on to discover David's real identity. Ada is also consumed with trying to decode the last message her father left for her to try and find out answers to all the questions she has, including answers to what is in the file called The Unseen World.
The story jumps between the 1980's, when David is declining and Ada is a young teen, to the 1990's when Ada is an adult working for a tech company, the 1940's and 50's when David was young, and ending in the present day.
While the novel has computer programming/science fiction elements in the A. I. storyline, the main focus is on the humans: Ada and David, but especially Ada. There are several parts that are heartbreaking and had me in tears, feeling for Ada as she tried to make her way in a world that was entirely foreign to her. The action in The Unseen World is cerebral rather than quick paced. Because of this it takes time and patience to reach the juncture where the story merges into a surprising conclusion.
The characters are well written and the backstory is worth the deliberate pace and the slowly unfolding mystery. The writing is excellent, with a carefully crafted story and intelligent plot. Ada's situation as a young girl is emotionally compelling as she tries to adapt to a world with no experience to handle it. The final chapter is a startling and satisfying conclusion, although at almost 500 pages the whole novel sometimes feels rather slow to reach the end.
Disclosure: My advanced reading copy was courtesy of the publisher for review purposes.