So, my idea,To Your Heart’s Context is an extremely large, leather-bound book, that when opened, always discusses the topics the reader most desires to read. For instance, if you are a Foundation researcher currently researching SCP-682, it will open to a page about SCP-682, which it names, the “Hard-to-Destroy Reptile”, listing known origin and age, current size and location, and a long description of 682 in slightly less official language than the official SCP-682 documentation, accompanied by an image of SCP-682. If you are a Foundation researcher researching SCP-682 and currently eagerly awaiting your lunch break, it will open to a page about lunch, and the Site cafeteria if applicable, and what you should have for lunch.
The encyclopedia contains information on extremely obscure topics, but only as far as human knowledge extends. A list of all known anomalies in the encyclopedia, for instance, would list all SCPs, currently in containment by any group, or not in containment at all, as long as the Foundation or other humans are aware of them. An anomaly on some distant planet that has not been explored before will not be listed; an anomaly observed by a single man living in Siberia will be listed.
If human knowledge is not aware of a misconception, then the encyclopedia will give the prevalent perspective. It will not say the earth is flat anymore, but it would if you lived in the 16th century.
I would think this is a Safe, but since sometimes people don’t know what they want (I could expand on that), perhaps it’s a Euclid? If the Foundation uses it to learn information it was not aware of about SCPs, then maybe it’s a Thaumiel.
Its special containment procedures would pretty much be just locking it up, I assume.
