Hit the marker outside the shipping container lot to get started.
Follow your objective to a sushi place, where Daisy will enter the first of many flashbacks. Continue to Interact with the sushi mascot until the authorities are summoned.
Fight off the cops, learning the quirks of Daisy's minigun.
When they're taken care of, you'll get an odd invitation and snap back to the present. Follow your objective to a marker in the river.
Flashback time, where you'll fight some robots, starting with the boom bots.
Blow them up before they get too close, then fight the patrolbots in the circle. Note that, even in a flashback, you may still attract attention from wandering LEGION patrols. Ignore them if possible, and focus on taking out the final enemy- a scout barragebot.
Back to the present, to a new marker and then reflashback- revisiting the same balconied room that was the LEGION Lair entrance in Heaven Sent. Kill everything there with your MAYHEM ability.
Back in the present, ascend the TTX tower. Do this using the same orange elevator cars you used in the very start of the game, when you were trying to find the Tranquility Temple site.
Up top you'll have a party flashback, which culminates in a LEGION attack. Mow them down, including the leading Blitztrooper Commander.
Finishing the fight causes Mixer to give you the location you're looking for. So, for all the trouble you went through with Daisy, someone could have just paged Mixer. Ah well, what's done is done, and this mission is.