Penelope and the Eighth Sacrament

What if you wake up tomorrow and realise you hold the keys to the world-that humankind would not survive without you. What if you were only thirteen years old? That is the world Penelope wakes into as soon as her clock chimes thirteen. She learns she is the Protector, the only one who can stop the dark knights of the Underworld from draining the world of all goodness. However, before her powers manifest she is just a vulnerable little girl. Can she survive the relentless attacks from the Underworld and find the Eighth Sacrament, a dangerous weapon that can destroy humanity? Is the world safe in Penelope's hands?