Nightmare Containment Lockdown Protocol Guide: How To Find Extra Loot In Destiny 2's Leviathan

gamespot.com:

The new Nightmare Containment activity is just one of the things to find on the newly arrived Derelict Leviathan in Destiny 2. Calus's ship is full of secrets, one of which being the hidden treasure chests that are only accessible when you complete a Tier 3 Nightmare Containment. You might have noticed a message about "lockdown protocols lifted" at the close of the event--that's your cue to try to find some secrets that'll reward you with extra loot.

The lockdown protocol refers to locked doors you'll find all over the Castellum. Once the protocol lifts at the end of a Containment activity, you can open some of those doors (usually two at a time). Behind them, you'll find additional treasure chests that seem to drop loot from the world loot pool.

Here's what to do to lift the lockdown protocol, where the chests are located, and how to find them after completing Nightmare Containment.

The lockdown protocol in the Castellum only lifts after you've driven out the Nightmares in the area, which means you need to complete the third tier of the Nightmare Containment activity. The good news is that you don't have to beat the boss Nightmare in Tier 3--you only need to get to Tier 3 and let the timer run out. When that happens, the Nightmare boss will escape, and you'll get a two-minute timer before the next round of Nightmare Containment activities can begin. During those two minutes, the lockdown lifts; watch for a message on your screen to let you know how many Castellum doors have been opened so you know how many chests you can find and open before the countdown ends.

There are lots of locked doors around the Castellum, which you can identify by their red lights, but only some of those are part of the lockdown protocol. You're