Before completion: When the dwarves took on Primordus, they learned much about traveling through Tyria's heated core. Learn this Mastery to travel long distances as the dwarves did.
After completion: Employ thermal propulsion to travel long distances.
— In-game description
The Thermal Propulsion mastery from the Ancient Magics mastery track allows players to access Thermal Tubes. These are objects found in Ember Bay and Bitterfrost Frontier that players can use to move large distances across the map.