Middle movies in a trilogy are tricky. As the filmmakers of The Hunger Games: Catching Fire (pictured) must have figured, second installments have to serve as a bridge between the first and third movies — and still satisfy on their own. They have to be self-contained, yet open-ended enough to make you come back for the finale. (Yes, in the case of Hunger Games, the third movie will itself be split into two parts, but Catching Fire is still the transition between the installment that set up the plot and characters, and the chapters that resolve everything.)
Of course, it helps if the trilogy is three movies related by something other than plot or character. (Think of Edgar Wright’s “Three Flavours Cornetto” trilogy – Shaun of the Dead, Hot Fuzz, and The World’s End — whose installments are linked mostly by casting, sensibility, and a motif involving ice cream.) Even so, the middle film still has to be the glue that holds the bookends together. Here, then, are 10 of those unsung heroes of the movie-trilogy world.