Tesla cant free herself from the erotic dreams sent to her by Samael, Prince of the infernal Seductors: the beautiful vampire is really at risk of falling towards the Evils side. Trying to avoid this danger, Harlan Draka and Caleb Lost find out that Samael, for the help he gave them not so long ago, was kept under surveillance by Nergal, the dangerous chief of Hells secret police To take Nergal off his back, Samael asks Harlan to recover a valuable artifact disappeared in the folds of the past: Dr John Dees mysterious black mirror, given to the alchemist by the self-appointed Angel of the Western Window, who actually was none other than the good devil, Nikolaus, in disguise. Allegedly, the mirror will endow its owner with a secure channel to the dangerous Black Dimension