This paper considers an ad hoc network, where a set of energy-rich mobile nodes, termed mobile relays, are used to facilitate relaying packets so as to mitigate the energy consumption of static nodes. Existing work has focused on link-level relaying behaviors. In this work, we show how to achieve route-level relaying by overhearing route control and data packets. This allows mobile relays to redirect the traffic of static nodes and thus reduce their energy consumption. As the relocation of mobile relays needs to dynamically adjust the current traffic condition, a dynamic relocation scheme of mobile relays needs to be designed. In this paper, we refer to the mobile relay deployment (MRD) problem and design a distributed protocol for mobile relays. In our protocol, mobile relays do not necessarily participate in the routing discovery process, so static nodes can quickly switch back to their original routing paths without reconstruction efforts once mobile relays leave their communication ranges. Simulations by QualNet are presented to evaluate the performance of our protocol as compared to link-level relaying.