'Something had been released into the night streets. It moved unnoticed and sucked the life from people. It caused slow painful death, but even those who could sense its presence were too scared to admit it was there.
And now, with quiet deliberation, it was heading for the street where I lived.'

Red Hellion lives opposite the creepy, tightly locked Torrington Park, or 'Viper's Green'. Walking home from school one day he meets Max, who is trying to break in. Before he knows it, Red finds himself sucked into Max's plans to discover the whereabouts of his father, who disappeared weeks before under sinister circumstances connected with the park. But neither Max nor Red realize just how much their lives are at risk. Their investigations into the park are linked to the terrible the legend of Medusa, and are about to lead them into horrific danger...