Lily Pierce is sick of being haunted. She decides to reconnect with her estranged father, a disgraced history professor, and learn how to draw upon a time of steel and blade when armor-clad knights rode out and dueled their monsters to the death.

艾迪（湯哈迪 飾）繼續與毒魔拍住上，行勻墨西哥到紐約尋找擁有超能力的人，更意外發現了一個威脅宇宙的黑暗洞口！二人遇上許多新舊朋友，另一方面，異生物出現更不斷追捕毒魔，雙方戰線更由地面打到上天空，鬥得難分難解。預告尾聲更疑似暗示艾迪與毒魔正面對死亡的威脅，有可能從此分離。難道共生體的結局要兩個只能活一個？