Di'Apollo's Instant Library

You conjure a portal to the extradimensional library of Callum Di'Apollo the Scribe, a seeminly endless grand study full of shelves of immaculately kept tomes and volumes.

Any number of creatures of medium size or smaller that are friendly to the caster can enter the portal along with the caster. The caster can use an action to close the portal and another action to open it for the duration. If the caster leaves the library, all other creatures are expelled from the library into the open spaces nearest to the portal, after which the portal closes and cannot be opened again unless the spell is cast again. All creatures are expelled similarly if they remain in the library until the end of the duration of the spell.

Visitors to the library can make Intelligence Checks (DC determined by the DM) to learn the location of four books with information of their chosing. The DC for individual checks vary depending on the obscurity of the information chosen - lower DCs are needed for more trivial and commonplace knowledge and higher DCs are needed for specialized and/or secret knowledge.

The caster can remove books obtained in the library from the demi-plane freely to a maximum of the number of books used in the casting of the spell as spell components; any books removed beyond this limit vanish in the holder's hand in a flash of golden sparks and inflict 1d4 fire damage per excess book as the books are returned to the library.

Additionally, the books used as spell components are added to the library's collection and their value drops to 0gp.

Time in the library moves at an equivalent rate to time on the material plane. Additionally, if the spell is cast in the same location everyday for a year, the portal becomes permanent and the duration is extended to Until Dispelled.