随着伦敦地铁网络下的谜团不断加深，莎莉·哈扎德和爱德华·塔恩必须沿着这条线索找到真相。但他们发现的不仅仅是一个尘土飞扬的废弃地铁站，而是一个奇妙的地下星际旅行综合体。随着时间的流逝，莎莉、埃德和他们的乌合之众必须在准备反击的同时与敌人战斗。这场战斗将使他们远离他们所知道的一切，前往另一个星球的表面……
With the mystery of what lies beneath London’s subway network deepening, Sally Hazzard and Edward Tarn must follow the scant clues to the truth. But what they discover is not just a dusty abandoned Tube station, but a fantastic subterranean interplanetary travel complex. With time against them, Sally, Ed and their rag-tag team have to take the fight to the enemy as they prepare their counterattack. And this fight will take them away from everything they know to the surface of another planet...
