While clues have existed that endosomal trafficking is associated with Alzheimer’s disease (AD), whether it plays a central role in the disease and if so how has remained unknown. Here we rely on recent genetic and cellular findings to construct a model proposing that traffic jams in the early endosome can act as an upstream pathogenic hub in AD. We also rely on an independent series of findings to suggest how the traffic jams can act as a unified mediator of downstream pathophysiology. The model predicts, therefore, that interventions designed to unjam the endosome carry high therapeutic promise.