The double-headed eagle signified an earthquake and in the Suquamish story, separated what is now Bainbridge Island from the Kitsap mainland after the eagle and a great monster plowed a trench in an epic battle the eagle eventually won. The eagle lives on in lore still.
This is but one of the oddities that the Tribal Officer adopts in his state of grief to assist in his fight against evil. He quits worrying about his own sanity when the tide begins to change and his ragtag crew embraces him as their project.