The shadows can't be held back forever.

Morgan Thomas has regained tenuous control over her body by imprisoning an alien creature within her subconscious, but the exertion of keeping the "thing" caged threatens to consume her. Running out of options to save herself and her dear friend Sheridan, Morgan reluctantly decides to make a trade: their lives for the alien's...and a powerful item called the Traveler.

After the exchange, Morgan and her friends return to Greenland under a cloud of impending doom. The Traveler is the ultimate tool to change the entire Earth's future, which could spell the end of the human race. As they wait hopelessly, unsure whether the aliens' leader will hold to their fragile truce, Morgan is contacted by a tree-like being from worlds away.

Gripped with horror, Morgan must reach deep within herself to find the path forward: Can she trust this monstrous being she's now entwined with? Or has the alien world polluted her beyond all chance of redemption?