This book looks at motion of particles using mathematical methods of physical observable values in General Relativity. It is shown that aside for mass-bearing particles and light-like particles "zero-particles" can exist in fully degenerated space-time (zero-space). For a regular observer zero-particles move instantly, thus transferring long-range action. Further we show existence of two separate areas in unhomogeneous space-time, where observable time flows into future and into past, while this duality is not found in homogeneous space-time. These areas are referred to as our world, where time flows into future and as the mirror Universe, where time flows in past. The areas are separated with a space-time membrane, referred to as zero-space, where observable time stops.