當一名護士同事在神秘的情況下死亡后，兩名巡回護士必須撥開醫院里重重秘密迷宮，才能揭露兇手。

　　British Army radiation drills at a remote Scottish base attract a subterranean, radioactive entity of unknown nature that vanishes, leaving two severely radiation-burned soldiers... and a "bottomless" crack in the earth. Others who meet the thing in the night suffer likewise, and with increasing severity; it seems to be able to "absorb" radiation from any source, growing bigger and bigger. What is it?? How do you destroy a thing that "feeds" on energy?

　　Follows a man whose pregnant wife gets murdered and despite the police investigation, the truth is unknown. He tries to find what happened, which confronts him with situations of suspense and terror.

　　《懸案密碼》系列的第三部：6年前，一只在海上漂流的瓶子在蘇格蘭被打撈上岸，然而里面的求救信卻被視為不祥之物，直到一位調查人員無意中看出了信件開頭用丹麥文寫著：救命！隨著卡爾和兩名下屬的破解，他們發現署名“保羅”的作者不僅確有其人，而且在寫下瓶中信后便下落不明......　　為何少年的家人不曾追究他的行蹤？難道他在多年前便已遭遇不測？正當調查陷入膠著，一起離奇車禍讓原本天衣無縫的邪惡罪行露出破綻，串起所有線索的卡爾這才明白，自己面對的并不單是一樁陳年舊案，而是過去十幾年來，許多破碎家庭的絕望呼救…