Found in the Dark

This time, the ripple of paracausal force is so strong that you can feel its pull like a gravity well.

Return to the cave in the Seclusion.

Details
Start point	Find a manifestation of Darkness in the cave in the Seclusion.
Requirements	Destined Heroes Quest Destiny 2: The Final Shape The Final Shape Activity Destiny 2: The Final Shape Wild Card Quest Destined Heroes Quest Destiny 2: The Final Shape Queens, Part I Activity Destiny 2: The Final Shape The Final Shape Activity Destiny 2: The Final Shape The Final Shape campaign Quest obtained fromDestined Heroes Quest Destiny 2: The Final Shape obtained fromHome, Part II Activity Destiny 2: The Final Shape Found in the Dark Quest (see above) Home, Part I Activity Destiny 2: The Final Shape Found in the Dark Quest (see above) Queens, Part I Activity Destiny 2: The Final Shape obtained fromHome, Part I Activity Destiny 2: The Final Shape Found in the Dark Quest (see above) Queens, Part I Activity Destiny 2: The Final Shape
Rewards	Dark Prismatic Grenade Dark Prismatic Aspect Dark Prismatic Super Ergo Sum Prismatic
Required for	Biting Cold, Home, Part I, Home, Part II

Found in the Dark is a The Final Shape post-campaign quest (Season 24, Echoes) given by Ghost after the Destined Heroes and Wild Card missions in the Pale Heart. It teaches the synergy between Light and Darkness and unlocks Prismatic abilities. Expect a couple of hours, mostly two story missions replayed with Caiatl and Zavala. It is also listed as a requirement toward the exotic sword Ergo Sum.

Head east in the Blooming to the cave in the Seclusion. Find the mirror-like portal (not the orange one) and synergize with the manifestation of Darkness inside.
Complete the mission "Home, Part I" in the Transgression with Caiatl, investigating Shadow Legion activity. Defeat Psions to drop shields, take antennae from Artillery Officers, and power the generators, then beat the Artillery Commander and the Prismatic Bound Omen that spawns.
Return to the Seclusion cave and commune with the Darkness again.
Complete "Home, Part II" in the Divide and destroy the Shadow Legion mining operations. Watch the Biting Cold status timer, use Psions and Unstable Power Units to destroy generators, and finish by destroying a Cabal tank at Zavala's farmstead.
Paracausal ripples unearth another manifestation: go back to the Seclusion cave and synergize it for the final reward.

The three Dark Prismatic items are collected across the steps.

Quest steps (from game data)