A journalist-in-over-his-head thriller, Defense of the Realm is a taut, tightly plotted conspiracy film that is very cerebral -- and very hollow. That last characterization may prevent some from embracing the film, for the hollowness results from a combination of an abundance of cynicism and a shallowness of characterization. So, if a viewer is looking for a film that is comforting and/or that explores the lives and motivations of its main players, he is bound to be disappointed by Realm. On the other hand, if the fun of the "game" is sufficient to a viewer, he will be well rewarded, for Realm's intricate plot is filled with labyrinthine twists and turns that will delight and dazzle aficionados of the "why did that happen and what does it mean" school. And director David Drury directs Realm cleanly and leanly, giving it a forward thrust that is essential to its success yet still finding time to craft some careful compositions that add impact to individual scenes without distracting from the flow. The cast does have to grapple with a lack of depth in their characters, and only Denholm Elliott succeeds in overcoming that challenge, somehow creating a three-dimensional human out of two-dimensional material. But the rest of the cast, especially lead Gabriel Byrne, make those two dimensions count for everything they're worth. Realm is suspenseful and exciting, and that will be more than enough for many viewers.