The ever-sensitive John Cusack plays David, a successful sci-fi author and widower who decides to adopt a child in an effort to find meaning in life and perhaps fill the void left by his late wife. His friend Sophie (Sophie Okonedo), who conveniently works at an orphanage, directs David's attention to Dennis (Bobby Coleman), a troubled boy who thinks he's from Mars and hides during the day in a cardboard box, afraid of burning up in Earth's atmosphere. Against the advice of his sister Liz (Joan Cusack) and under the suspicious eye of social workers, David takes Dennis into his home.
The film follows David's developing relationship with Dennis, and here director Menno Meyjes succeeds only in poking at the viewer's heart -- he comes nowhere close to piercing it. Nothing truly dramatic happens and the turning points lack emotional intensity. Where it comes close, it is sappy. The film doesn't jerk any tears and the happy ending is predictable.
One of the chief flaws of the film is a vast discrepancy between the boy's character as portrayed versus what the viewer is led to believe. The script suggests that he has attachment disorder, but he's just too cute and inoffensive to convey the disturbing reality of that condition. The inevitable bond between the two could only happen so quickly and easily in Hollywood. There are also some unnecessary, beguiling hints that the boy might actually be from Mars, and a confusing, undeveloped relationship between David and his late wife's best friend Harlee (Amanda Peet).
In this father/son love story, Martian Child explores the familiar theme of conformity as the price of acceptance -- mirrored in David's own relationship with his publishers -- but it unfortunately gets lost in a fairy tale devoid of magic.