Detect Spellbook

For the duration, you sense the presence of spellbooks, spell scrolls, and any other encoding of magical knowledge that conveys knowledge of how to cast a spell, within 30 feet of you. If you sense magic in this way, you sense the size and location of any such encodings, and you learn the school of magic of the spell conveyed, as well. If you pass a DC 10+spell level intelligence check, you also learn the name of the spell that is encoded, specifically.

The spell can penetrate most barriers, but it is blocked by 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt. However, the block itself is perceptible you.