Conversation so far:
What was he doing?
In 1955-1956, Heyerdahl organized the Norwegian Archaeological Expedition to Rapa Nui (Easter Island.
Who was apart of this team?
The expedition's scientific staff included Arne Skjolsvold, Carlyle Smith, Edwin Ferdon, Gonzalo Figueroa and William Mulloy.
Heyerdahl and the professional archaeologists.
What did they do while there?
archaeologists who travelled with him spent several months on Rapa Nui investigating several important archaeological sites.
What where highlights of the dig?
Highlights of the project include experiments in the carving, transport and erection of the notable moai, as well as excavations at such prominent sites as Orongo and Poike.
What else did this dig produce?
two large volumes of scientific reports (Reports of the Norwegian Archaeological Expedition to Easter Island and the East Pacific) and Heyerdahl later added a third (The Art of Easter Island).
What did this do?
Heyerdahl's popular book on the subject, Aku-Aku was another international best-seller.
What else did he produce?
In Easter Island: The Mystery Solved (Random House, 1989), Heyerdahl offered a more detailed theory of the island's history.

Question: What was this book based on?
Self-contained rewrite: What was the book "In Easter Island: The Mystery Solved" based on?