During rest, hippocampal place cells replay activity sequences, but it is not clear whether grid cells in the medial entorhinal cortex are involved in this replay. Here, grid cell activity in resting mice that had navigated a Z-shaped track was spatially coherent with that of place cells, with grid cell activity lagging ∼10 ms behind that of place cells. So, grid cells may be involved in relay and so may have a role in spatial memory consolidation.