it was necessary that i should return without delay to geneva , there to watch over the lives of those i so fondly loved ; and to lie in wait for the murderer , that if any chance led me to the place of his concealment , or if he dared again to blast me by his presence , i might , with unfailing aim , put an end to the existence of the monstrous image which i had endued with the mockery of a soul still more monstrous .