Echo didn't stop at one signal.
By the time Jin reached the open stretch of cracked avenue where the sound had led him, Echo was already standing atop the shell of a gutted bus, both hands pressed flat against the metal, driving pulse after pulse of concentrated sound out across the ruined skyline, deliberate and unmistakable, a beacon aimed directly at the thing they'd all spent the last hour running from. Each pulse rattled loose glass free from nearby windows, the rhythm of it steady and unbroken, like Echo had no intention of stopping until something actually answered.
"You're not supposed to be calling it in yet," Jin said, breathless, jogging the last stretch to join him.
"Well, everyone is so far apart," Echo said, not looking away from the horizon. "I need to make sure that everyone would make it back over here."
