Written and directed by Tim McCanlies (1998's "Dancer, Texas Pop. 81"), "Secondhand Lions" aspires to be a nostalgia-filled coming-of-age story set in Texas, while at the same time a fantastical adventure complete with sword fights and daring escapes set in Africa. While each individual section might have worked on their own with further story and character development, they do not mesh well when interweaved together. What is left, then, is a well-meaning trifle, earnestly performed but way too bland and vanilla to elicit much in the way of rooting interest or lasting memorability.

Set in the 1950's, soft-spoken 12-year-old Walter (Haley Joel Osment) is left by his self-involved mother, Mae (Kyra Sedgwick), to stay with his two eccentric great-uncles, Hub (Robert Duvall) and Garth (Michael Caine), for a few months. Rumor has it that Hub and Garth have piles of money stashed away somewhere on their propert, and the money-and-man-hungry Mae's goal is for Walter to win the graces of his relatives so that they will leave the cash to them in their wills. Without a telephone or television, Walter has no choice but to spend all his time with Hub and Garth, who mostly live off their Texas land and delight in pulling out rifles on traveling salesmen. In the process, he begins to greatly admire and look up to his uncles, whom he comes to realize serve as more fit and caring parents than his own mother ever has. Meanwhile, Walter is fascinated by the stories Garth tells him of their adventures years before in Africa, where Hub won the heart of a dangerous Sheik's wife-to-be, Jasmine (Emmanuelle Vaugier).

While the storytelling sequences set in Africa do, indeed, reveal themselves at the end to serve a true purpose, they are ineffectively carried out. The love story between Hub and Jasmine is so undernourished that its aftermath holds no weight in the 1950's scenes, while its moments of adventure play like scene rejects from "The Princess Bride" and "Raiders of the Lost Ark." Because they do not work, the viewer is taken out of the immediate plot every time Garth starts to spin one of these tales. Had the coming-of-age story been more involving, this would be a small price to pay. As it is, the Africa scenes only expose Walter's story to be one that is too subjectively clean-cut and aimless.

One never really gets a firm grip while watching "Secondhand Lions" where its rooting interest should lay. The story of Walter and his uncles, while offering up some amiably heartwarming moments (a heart-to-heart between Walter and Hub, and the scenes with an unlikely pet lion spring to mind), is so lightweight that it often threatens to simply drift away. Had writer-director Tim McCanlies zeroed in on exactly who Walter was and the full experiences he had as he came of age, rather than focusing solely on the loopy sincerity of Hub and Garth, the results would have not only been more interesting, but also more truthful to the act of a young boy growing up. Only near the conclusion, when Walter comes into his own and uses the wise lessons his uncles have taught him to finally stand up to his mother, does the film hold any sort of emotional weight.

In his first adolescent film role, 15-year-old Haley Joel Osment (2001's "A.I.: Artificial Intelligence") initially startles at just how deep his voice is getting and how much he has grown up since his Oscar-nominated role in 1999's "The Sixth Sense." There is no doubt that Osment has acting talent to spare, but he is at that tricky transitional phase in his career where he is sometimes a little shaky in balancing being both a child and, now, a young adult. In some scenes, Osment is stiffer than he ever has been before, but that may have just been a character choice, since his Walter is introverted and unsure of where he belongs. When he does come into his own in the final twenty minutes, Osment is exceptional, lending real poignancy to these dramatic moments.

As Hub and Garth, who learn from Walter the value of life and living every moment to its fullest, veterans Michael Caine (2000's "Miss Congeniality") and Robert Duvall (2003's "Open Range") are such brilliantly knowledgable performers that it is easy to overlook just how good they really are. With decades of acting behind them, what they do feels effortless. Kyra Sedgwick (2002's "Personal Velocity") is very good as Walter's mother, Mae, as she brings unexpected depth to a character who cares about her son, but is too often blinded by her own selfishness.

"Secondhand Lions" is filled from top to bottom with real heart, so much so that it is unfortunate the film as a whole does not quite succeed in what it sets out to do. Flighty when it should be more truthful, the movie is low-key in the extreme, desperate to win over children and adults without offending anyone. Its own aloofness bleeds into the viewer's reception. When, at the end, you come to realize Walter has grown up to be a cartoonist, you are left questioning how he came to choose this as a profession, since he is never seen in the 1950's scenes doing any sort of artwork or even mentioning an interest in drawing. Just who Walter is, the viewer is regrettably never given a chance to find out.