Preface.- Quantum Gravity: Whence, Whithter? (Claus Kiefer).- Local Covariance and Background Independence (Klaus Fredenhagen, Katarzyna Rejzner).- The "Big Wave" Theory for Dark Energy (Blake Temple).- Discrete and Continuum Third Quantization of Gravity (Steffen Gielen, Daniele Oriti).- Unsharp Values, Domains and Topoi (Andreas D?ring, Rui Soares Barbosa).- Causal Boundary of Spacetimes: Revision and Applications to AdS/CFT Correspondence (Jos?...