Step 1: Decrypt an Echo Engram in Destiny 2
The first step to kickstart the A Familiar Voice quest for the Echoes episode is to travel to the H.E.L.M. and interact with the War Table to decrypt one of the Echo Engrams you have already collected during your progress in the Pale Heart campaign missions.
Note that the War Table will disappear and instead be replaced with Failsafe right after completing A Familiar Voice, so keep that in mind if you are wondering where the table went.
Step 2: Thwart the final shape in Destiny 2
This step may have seemed glitched to many, but it now makes sense with a clear understanding of how episodic content will unlock throughout this new era of Destiny 2. To thwart the final shape in Destiny 2, you will have to complete the main Destiny 2 campaign, with the official release of the Echoes episode finally triggering the completion of this step. Every Guardian that has previously completed the events of The Final Shape will be spawned straight into Nessus at Step 3.
Step 3: Complete Mission: Meteoric on Nessus in Destiny 2
Failsafe is back, and the initial task in Mission: Meteoric is to contact her at the ship’s wreckage in Nessus at the Exodus Black region. Speak with Failsafe, and you will find out that she has been undergoing a quarantine thanks to the Vex. To break it, you will need to head back outside and disrupt three different Confluxes. Interacting with them will do the trick, but any incoming damage will stop the progress, so clear the Vex presence in the area first.