DREDGE endings: the Collector’s ending and the secret ending
DREDGE has two endings. Handing the Collector all five relics gives one; meeting the Old Mayor and the Lighthouse Keeper, then returning the Collector’s book to the sea, gives the other.
DREDGE has two endings, and both turn on the Collector at Blackstone Isle. The first follows his instructions to the last relic. The second depends on learning what his book is before you finish.
For the first ending, hand the Collector all five relics: Rusted Music Box, Ornate Key, Shimmering Necklace, Antique Pocket Watch and Jewel Encrusted Band. He waits for a thick fog, then has you sail west of Greater Marrow after one in the morning, to the place where his wife was lost. He drops the relics overboard one at a time, the music box and its key last. A woman rises from the water with an enormous creature behind her, and the closing scene shows Greater Marrow in ruins. This ending earns Unshackled.
The second ending needs the Old Mayor, who keeps to Makeshift Dock. He takes you for the Collector, talks about the fog, the aberrations and the book, and sends you to the Lighthouse Keeper in Greater Marrow. After that conversation, go back to the Collector and challenge him about his book. The confrontation shows that the Collector is your own reflection in a mirror, and it leaves the Book of the Deep in your hands.
Take the book to the Lighthouse Keeper, who turns the lighthouse beam on the place where it must return to the sea. Throw it in there: the Leviathan swallows you, the boat and the book, the fog lifts, and Greater Marrow rests under a clear night sky lit by an aurora. This ending earns Sated.
If you reach the second ending first, the first ending plays later with changed lines: the Collector fades from his mirror, and you are the one who reads from the book and throws the relics into the sea.