Once per long rest, you can move up to 60 feet in one second to a position that you can see when you start. Anyone looking at the path of travel rolls a perception test of DC15. If succeeded, they know that something moved in front of them, but not what or where the final destination was. Otherwise, the movement is not detected or heard.
Granted by the god of storms, Talos, lightning speed is given to those who serve him and do his bidding.