This letter develops a single-hop fast accurate and energy-efficient time synchronization protocol for wireless sensor networks. The protocol is designed to operate in harsh environments and is based on a resistive electrical network metaphor. It treats the nodes' times as the states of a discrete decentralized unconditionally stable dynamical system. The synchronizer monitors the evolution of these states during the transient phase to determine the instant at which the time encoded by a state is close to the master node time. The procedure can yield high quality time estimates with accuracies that are fractions of the communication cycle. The synchronization method is developed and its capabilities are demonstrated by simulation and physical experiments on the MICA-Z wireless sensor network.