Telepathy

8th-Level Divination
Casting Time: 1 action
Range: Unlimited
Components: VSM (a pair of linked silver rings)
Duration: 24 hours

As in the Player's Handbook with the following added:
At Higher Levels. When you cast this spell using a spell slot of 9th level or higher, you can connect to one additional creature for each slot level above 8th. All creatures connected with each other in this way can telepathically communicate freely with each other.

Source: PHB 281

Changelog