The Library

An unlabeled door in the lower levels of a library opens to somewhere new. A spell gone wrong casts you into a strange new plane. An ancient order opens up it's hands, and asks you to join. 

You have made a pact with the Library. Known by many names, it has a power not quite bound by the material plane, ancient, full of items more rare and wonderful than can even be imagined. Bound to its service, you are tasked with protecting it's interests and acquiring new assets. 

Extended Spell List

1st - guiding bolt, identify
2nd - locate object, silence
3rd - clairvoyance, tongues
4th - divination, Leomund's secret chest
5th - geas, legend lore

Hidden Doors

When in a Library, Archive, Repository, or other place of knowledge and learning, you may search for an entrance to the Library you serve. Anyone accompanying you may enter as well, but be warned, admittance to the Library is not without cost. 

Secrets of the Library

You are connected to the Library, allowing it to access your mind. You gain proficiency in perception. As a bonus action, you may choose one creature you are in combat with, and ask the Library to grant you insight into it's nature. Choose on of the following aspects to learn: Creature Type, Armor Class, Senses, Saving Throw Modifier of your choice, Damage Vulnerabilities, Damage Resistances, Damage Immunities, or Condition Immunities. This ability recharges on a short rest. 

The Price of Knowledge

At 6th Level, you have gained the trust of the Library, and it offers you it's power. Using a bonus action you may offer a rare and valuable item or memory to the Library in order to regain a spell slot, at a cost of 200 gp/slot (price to vary depending on local economy).

If the item is particularly rare, magical, or interesting to the library, it counts as double what it is worth. Any book the Library does not own counts for double what it is worth. The Library can choose not to accept items if they do not hold sufficient interest or if it has an undue amount of that particular item. Pricing of memories depends on their value and interest to the Library. Valuable memories include close connections, plot-relevant details, memories of skills (removing all or part of a proficiency bonus), proficiencies, languages learned, or spells.  

The item traded does not have to be yours, but it must be in your possession, and it cannot be attuned to someone else. The memories need not be yours, either, but you must be in possession of them, not merely viewing them.

Haggling the Library over cost requires at least one action. 

Know Thine Enemy

At 10th level, you may use your bond with the Library to glean tactical information relevant to your pursuits. During your short rest, you may commune with the library to gain information about your foes.  Select a race to gain knowledge of. You gain expertise on History and Nature checks about your chosen enemy, and resistance to a related damage type of your choice, excluding bludgeoning, piercing, and slashing damage.  

Lending

You have proven yourself a valued asset to the Library. At 14th level, you are able to borrow from it's collection. 

Once per long rest, using an action, you may summon a magical item held in the library whose name you know. The item appears in your hands until it leaves your possession, someone attempts to attune with it, or ten minutes pass. Rarer and more powerful items may require a check to convince the library, as will consumable items or items with charges that cannot be easily replenished. Items that are destroyed or become powerless on use cannot be summoned; the library wants to maintain it's collection. 

You may also use this ability to summon any book whose title and author you know. This does not require a long rest to recharge, and the book remains until it leaves your possession or someone attempts to copy a spell held within.