There are well known connections between the random walk on a graph, and its topological and spectral properties. In this talk we will define a new stochastic process on higher dimensional simplicial complexes, which reflects their homological and spectral properties in a parallel way. This leads to high dimensional analogues (not all of which hold!) of classical theorems of Kesten, Alon-Boppana, and others. Based on a joint work with Ori Parzanchevski.