Such an odd story… they announced last week that two of Darwin’s notebooks must have been stolen, after being missing for 20 years. Imagine a library so big that it takes them 20 years to decide for sure if something is just misplaced or definitely not there at all!

Twenty years ago, two historic notebooks belonging to the renowned naturalist Charles Darwin were found missing from the archives at Cambridge University Library. The tiny books recorded Darwin’s thoughts after he returned to England from his famed voyage aboard H.M.S. Beagle, as he grasped toward ideas that would form the foundations of modern evolutionary biology.

Now, the library has said it believes the notebooks were most likely stolen, and it launched a public appeal for any information about their whereabouts on Tuesday. The local police say they have asked Interpol to place the items on its Stolen Works of Arts Register.
The library, which houses the largest collection of Darwin’s writings, has described the missing notebooks as “priceless” but nevertheless estimated their value at “millions of pounds.”

Read more: Two Darwin Notebooks, Missing for Decades, Were Most Likely Stolen