Batman: Arkham Knight - Penguin, Batwing, Disruptor, Harold’s Repairs

It seems that Penguin has been supplying weapons to Arkham Knight, operating under the guise of the North Refrigeration company. Before tracking him down, however, you should go collect Lucius' new Batmobile upgrade.

Equip a new Secondary Weapon for the Batmobile

Hop in your vehicle and follow the waypoint marker to the airdrop location. You now have the upgrade that you selected back at the office a little earlier. Deal with any drones that swarm in on your position then prepare to rendezvous with Nightwing nearby.

Before continuing, take a look in your mission select menu and you'll spot that the Armoured and Dangerous mission is now unlocked. This tasks you with hunting down all of the militia's APCs as they roam around Gotham. There are three to be found on each island.

Rendezvous with Nightwing to get intel on Penguin's whereabouts

Once you leave the menu, you'll likely be alerted to the presence of another mutilated body on a rooftop in Kingston. Feel free to investigate if you wish, otherwise follow the objective marker to your agreed meeting point with Nightwing. When you reach the waypoint, climb out of the Batmobile then grapple your way up to the top of the Ranelagh Ferry Terminal building.

Judging by the North Refrigeration company's trucks in the yard below, it seems that Penguin is operating in the area. When you're done talking with Nightwing, graciously accept the Disruptor weapon then prepare for the next leg of your journey.