The public will be able to see the notebooks of Charles Darwin that were mysteriously returned after being lost for over 20 years.
These include his Tree of Life sketch, which explores the evolutionary relationship of species.
In a pink gift bag, the books were anonymously returned in April.
On Saturday, the University Library will host the Darwin in Conversation exhibition.
Two notepads of postcard size were left anonymously in a bag containing the blue notebooks and a plain brown envelope with the message "Librarian Happy Easter X."
After being requested to be taken from a special manuscripts storage room to be photographed, the notebooks were last seen on November 2000.
They were transferred to a temporary studio, but the library found them missing two months later.
These notepads, valued at millions of pounds, were returned and are being displayed in the new exhibition for the first-ever time this century.
The library stated that there was no CCTV at the location where the package was dropped. It is not yet known who took or returned the books, but that they were well cared for.
The case involved the Cambridgeshire Constabulary, however, a spokeswoman stated that "the investigation was now being filed pending any new information being made".
The 15,000 Darwin letters that Darwin received and wrote during his life have been used to create the new exhibition. This is the largest collection of Darwin-related material in the world.
Dr Alison Pearn is the associate director of Darwin Correspondence Project. She stated that Charles Darwin is one the most well-known names in science, and we can all learn more about him through his letters.
"Darwin's letters can be unexpectedly warm, funny, and engaging.
Charles Darwin was a young, unassuming adventurer who also became a father figure and a celebrity. He had an insatiable curiosity about the world.
Other than the notebooks, there are also Darwin's first edition of "Origin of Species", the squeaky beans that became a viral hit after a video of their cleaning was released last year, as well as illustrated sketchbooks from HMS Beagle's voyage.
These pages, which are rare from Darwin's original draft of "Origin of Species", will also be on display. They were kept by Darwin's children to use as drawing paper.
The Darwin Correspondence Project was founded at the library in 1970. It consists of staff who work to transcribe and publish in print (and digitally) every letter Charles Darwin received and wrote.
To coincide with the exhibition, the library will publish the 30th and last volume of correspondence this year. This marks the end of one the longest-running humanities projects in the world.
Professor Jim Secord, project director, stated that Darwin was dependent on letters. Darwin received specimens of animals and plants from all parts of the globe, including from Brazil, and from Southeast Asia.
He spent an hour every day reading them, and another hour responding to them - some fan mail - using them both as research tools or pleas for assistance. He copied the notes he had written in the margins and cut them up.
"Darwin is a well-known scientist, but this exhibit shows that he was just one of many voices in a large global network of conversations that helped to propel scientific discovery during Darwin's lifetime."
The Darwin in Conversation exhibition is open from 9 July to 3 December at Cambridge University Library. It will then transfer to New York Public Library by 2023.
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