MISSION 12 – Protecting Ivy's Plants
Objective: Head to the Wayne Tower parking garage and collect Ivy plant tracking device
Yet another short mission. Hop back in the Batmobile and floor it to the tower's parking garage to pick up a new sonar for your sweet ride. When you arrive at the tower, it seems things have gone awry. As you enter the parking area below, twenty enemy drones will emerge from the woodwork (or at least parking area walls) and begin to attack. The area is fairly roomy, so you will have space to maneuver at least.
Use the pillars to block incoming guided missile attacks and don't forget to use your newly upgraded secondary weapons if you can. Using the virus secondary can take the heat off you for a few seconds to let you catch your breath, especially on the triple shot firing drones. Basically keep moving and firing and you should be fine (you should be plenty experienced in tank combat by now). Hopefully you've bought the upgrades for the 60mm cannon's reload speed by now or this is going to be a painful fight.
Objective: Use the Batmobile Sonar to locate and release Ivy's plant on Miagani Island
As you leave the parking area of Wayne Tower, there will be another eight drones on the streets. So it might make life easier to take them out before you start your search. After that's taken care of, use your new sonar ability (press LS when in battle mode) to trigger it and reveal any plant roots below. When you find the right position (shown by an orange dot in the middle of a massive root system), hold the LS down to free the plant.
Objective: Protect Ivy's plant from the Arkham Knight's militia while it matures
Goons won't like what you are doing. So beat them up. You'll be dealing with a bruiser, a medic and about eight regular militia enemies on the rooftop. Remember to use your Batclaw (LT + Y/ Triangle) to deal with the electrified enemies. Keep kicking ass until they are all prone and watch the scene play out as the mission ends.