The End of the World: I Have a Book of Prophecies

'The soil under my feet... Smells fishy... It's not what it used to be... It's over! ' 'It's black and crawls along the cracks of the bricks... It's sticky... It can't be wiped off...' 'Just one chance... Just one chance...' 'The cock crows three times... Chase the brightest side... Don't stop... Don't look back...' What exactly is this book. Where did it come from, and why did it appear in Su Yu's hands. What is hidden behind the darkness?