This Lenape Tribe's Cloak is an old cloak made of deer pelt and bird feathers that allows its wearer to become intangible, to pass through solid objects when it glows. When the user puts the hood up their whole body becomes intangible and anything they touch becomes intangible. However, when Agent Pete Lattimer touched only a feather off of the cloak only part of his arm became intangible.
It was discovered in New York City after a flawless art heist was pulled off; according to the safe's records, its door was never even opened when the heist was committed.
The Lenape had a story they called "The Man They Cannot Hold" and its about a great hunter who was killed by a witch, and was sent on his way with a ceremonial burial dress made by a Sachem. He asked that when he died that his body should be thrown into the river where his Guardian Spirit resided. Six days after he had died he reappeared and claimed he was hiding in an underwater cave all that time.
It's probable that he reached the cave by using the cloak to move through the rock where he found the underground cave.
The original use of this artifact is unknown.