Thoughtstone

Wondrous item, rare (requires attunement)

A thoughtstone is a magical communication device that looks like a small, clear, smooth stone. When placed upon your temple, it becomes invisible and intangible. It can be removed only if you will it or if you die.

Wearing it allows you to connect to a telepathic network created and maintained by the Inverted Pyramid, as long as you are within 2 miles of the Inverted Pyramid itself.

As a bonus action, you can use your connection to the network to detect whether an individual whose name you know also has a thoughtstone and is within range of the Inverted Pyramid. If so, you can use an action to attempt to set up a telepathic link through which the two of you may communicate. The contactee can automatically tell that someone seeks to communicate mentally with them, and they gain a sense of your identity (it cannot be masked or disguised) and can allow open telepathic communication between the two of you. Once a connection is established, either of you can attempt to get others to join in on the mental discussion, setting up additional thought links as described above. Communication can last as long as the parties are willing, conscious, and within range.

You can refuse communication with anyone who attempts to contact you through your thoughtstone, and can specify that you never accept communication from a specific person.

You can mentally turn off the thoughtstone at any time, and it cannot send or receive communication until you reactivate it again.

Spells or effects can never be transmitted through a thoughtstone. It doesn’t give you any sense of the other person’s location (although they can tell you). Magical barriers (such as a wall of force) may interfere with thoughtstone communication. The Inverted Pyramid can deactivate any thoughtstone at any time, effectively removing it from the telepathic network.