It was a chancy proposition for 20th Century Fox to tackle the "Planet of the Apes" franchise once more following Tim Burton's dismal 2001 remake, but the gamble paid off. In addition to taking the story in a different direction that pinpointed the events leading to a fateful simian uprising, 2011's "Rise of the Planet of the Apes" captured many viewers' imaginations through the resilient motion-capture effects which brought its primates to startling life. As solid as the film was as a cautionary adventure, one stemming from the precarious testing trials of a new drug intending to regenerate brain cells, what anchored director Rupert Wyatt's breakout hit was the complicated relationship between hyper-intelligent ape Caesar (Andy Serkis) and the caring scientist (James Franco) who welcomed him into his family. In Matt Reeves' (2010's "Let Me In") technically stirring follow-up, "Dawn of the Planet of the Apes," Franco is out and the main attractions are most definitely the title animals. With an uninspired new group of human characters to contend with, however, half of the film becomes a dreary, lopsided slog. Returning screenwriters Rick Jaffa & Amanda Silver and new series scribe Mark Bomback (2013's "The Wolverine") seem to have no idea what to do with them, and the finished product suffers because of it.

It has been ten years since a simian flu outbreak swept across the globe, claiming the lives of hundreds of millions of people in the process. In a dystopian, moss-grown, mostly deserted San Francisco, the survivors are facing certain doom unless they can find an alternative power source that will get their radio transmitter working long enough to call for help. Their only hope to generate said power lies with a nearby dam in the apes' wooded lair, but making peace with this mistrusting, highly evolved species will be a necessary hurdle they must first jump. The initial run-in between man and beast goes disastrously, but Caesar recognizes in Malcolm (Jason Clarke) the same propensity for goodness he saw in the people who raised him. His willingness to help out the humans creates a contentious divide among their fiercely loyal tribe that only deepens when the treacherous Koba (Toby Kebbell) makes a manipulative bid to overthrow Caesar's rule and target man for annihilation.

"Dawn of the Planet of the Apes" strives to be more than big-budget, empty-headed, summer-movie eye candy, but just because it plainly touches on (read: spells out) themes involving abuse of power and the fundamental ways in which man and animal are alike doesn't make it any less of a hollow experience. When the film is focusing on Caesar and his torn feelings over trusting the human interlopers and protecting his race, it is at its most enthralling. His relationship with his sons and the mother of his children, Cornelia (Judy Greer), is too simplistically sketched, but more involving is the disintegration of his alliance with the vengeful, grudge-holding Koba, who sees humans only as enemies. An attempt to position Caesar's growing respect for Malcom as a reminder of his friendship with Franco's Dr. Will Rodman doesn't work because there is so little time dedicated to it. Because this thread is weakly developed—and the human characters as a whole are such dullards—the picture misses out on its greatest chance for an emotional payoff.

Andy Serkis (2012's "The Hobbit: An Unexpected Journey") and Toby Kebbell (2013's "The Counselor") are outstanding as Caesar and Koba, their fully engaged performances photographed on location via state-of-the-art motion-capture technology. The subtleties of their facial expressions and body movements are seamlessly converted to onscreen creations who come to life as vividly as if there were no CG effects involved at all. Unfortunately, the actors in the human roles don't seem half as real as the apes, marred by a restrictive screenplay that gives them little to do and even less depth. Jason Clarke (2013's "The Great Gatsby") and co-stars Keri Russell (2013's "Dark Skies") as girlfriend Ellie, Kodi Smit-McPhee (2012's "ParaNorman") as teenage son Alexander, and Gary Oldman (2012's "Lawless") as their stern, grieving leader Dreyfus commit to their parts, but there isn't much to their parts to begin with. It is mentioned that Malcolm lost his wife to the virus, Ellie lost her daughter, and Dreyfus' actions are informed by his anger over what happened to his family. Now that Ellie is romantically with Malcolm, she is hoping to break down Alexander's aloof exterior and bond with him. This is the extent of what is learned about these people, and after a while most of their participation in the plot peters out as the conflict between Caesar and Koba takes center stage. Spending time with these characters becomes frustrating, the amount of care brought to them in steep contrast to the attention paid to the movie's visual artistry.

There is a scene about midway through "Dawn of the Planet of the Apes" that is illustrative of the film's squandered potential. When Malcolm manages to flip on the power generators, he and his group are drawn to a gas station in service for the first time in almost a decade. As a recognizable song drifts into the night air ("The Weight" by The Band), they are confronted with what is presumably the first music they have heard in years. It is an effective moment, but only due to the strength of its soundtrack cue. By not holding long enough on the characters or properly capturing their feelings, the situation's dramatic impact is severed. This same problem happens again and again, the few wholly potent segments coming from the quandary Caesar faces as he realizes his own kind can be just as wrongheaded and dangerous as any human ever could. A climactic showdown between himself and Koba sparks with tense excitement, yet the narrative is otherwise curiously low on action with next to no prominent set-pieces of note. It is worth mentioning, as well, that as stupendous as the apes look, the other animals—a herd of deer, a grizzly bear—are surprisingly inauthentic, stunted with the too-smooth motions inherent to synthetic beings built entirely on a desktop. For all of Caesar's complexity, "Dawn of the Planet of the Apes" lacks intimacy and personality in all that surrounds him. If humankind is as insipid as the way it is portrayed here, why should it make a difference to the audience whether anyone lives or dies?