This article proposes a deterministic foundation for quantum mechanics and spacetime based on a Unified Dynamic Network Theory (UDNT), in which nodes and links form the sole constituents of physical reality. Space, matter, and time are not independent entities but emergent aspects of the same underlying network dynamics. Nodes undergo continuous join—split cycles, producing the intrinsic oscillatory behavior normally attributed to zero-point fluctuations. Distance is defined by the typical number of network transitions between two regions rather than by pre-existing geometric separation. Phases attached to the network links enable multiple microscopic paths to coexist, providing a deterministic mechanism for superposition, interference, and wave-like behavior. Spin is incorporated through a minimal two-component internal structure of the link phases.Matter arises as a stable pattern of enhanced connectivity that retains its identity under the network’s evolution. In this way, space and matter are unified: particles are excitations of the same relational structure that constitutes the geometry around them. Such excitations naturally modify the surrounding network, suggesting a path toward a geometric description of gravitation. Quantum entanglement is reinterpreted as the presence of direct nonlocal connections that impose correlations without transmitting signals through space. In this framework, quantum randomness is not fundamental but emerges from the complexity of the network’s deterministic evolution. The UDNT approach thus offers a coherent relational picture in which spacetime, matter, and quantum phenomena jointly arise from a single, evolving network substrate.