Destiny 2's Season of the Haunted sends players back to the Leviathan, a huge Cabal ship that's the home of exiled Emperor Calus and the former location of Destiny 2 vanilla's Leviathan raid. The Leviathan is the home to the new seasonal activity, Nightmare Containment, which tasks players with using a special device to capture the evil Nightmare creatures we first saw introduced in the Shadowkeep expansion. Containment has a lot of moving pieces and requirements you'll need to understand to maximize your time with the activity and earn the best rewards you can.
First, it's worth noting that Nightmare Containment is a Public Event similar to the Altars of Sorrow event on the Moon. The event can be triggered in the Derelict Leviathan's patrol zones, and features multiple tiers you'll need to complete to get your rewards--just like the Altars. There are also new currencies you'll want to earn throughout the course of completing the activity so you can maximize your weapon and armor gains. Here's everything you need to know about Nightmare Containment in the Season of the Haunted.
How to launch Nightmare Containment
There are two options to get into the Derelict Leviathan, but either will let you take part in the Nightmare Containment activity.
The first thing about Nightmare Containment that's likely to trip you up is the option to either launch to a Derelict Leviathan location, like the Castellum, or to jump into Containment directly. From the Moon Director screen, you can find the Derelict Leviathan node on the left side, which contains those two options. The truth, however, is that both can get you to Containment, and it doesn't really matter which you choose.
