Adamantine Tablet

This hard black tablet cast of adamantine has the dimensions of an average book, though weighs considerably more. While holding the tablet in your hand, you gain the ability to cast comprehend languages which you can cast 3 times a day without expending a spell slot. 

The first message the tablet contains is a contract to accept the responsibilities and consequences of taking the tablet. Additional messages will appear on the tablet thereafter. 

The tablet begins to grow warm when a message appears on it. If the tablet is not checked within the first hour of the message being sent, it will cause items near it to catch fire.