This movie demonstrates vividly the essence of the network controllability paper: How to control a complex network with minimum number of nodes? For a given directed network, we calculate its maximum matching: a largest set of edges without common heads or tails. From it we identify the minimum set of driver nodes to control. By injecting signals to those driver nodes, we can fully control the network. There is a "cactus" structure underlying the controlled network, which is the "skeleton" for maintaining controllability. We show the cactus structures for both random networks and real-world networks in the movie.