Like a post-apocalyptic Pinocchio, No. 9 (voiced by Elijah Wood), the diminutive, anthropomorphic hero of director Shane Acker’s computer-animated 9, awakens to the lifeless body of his human creator and sets forth into a decimated industrial landscape that calls to mind London after the blitz. There, he encounters some like-minded (and similar-looking) fellow travelers, each duly numbered, 1 through 8, in the order they were created. No. 1 (Christopher Plummer) is the self-appointed leader, suspicious of outsiders and potential threats to his authority; No. 2 (Martin Landau) is the kindly inventor who welcomes No. 9 into the fold; No. 5 (John C. Reilly) is a loyal, selfless lieutenant; No. 7 (Jennifer Connelly) is the token she-whatsit; and so on. Together, they try to fend off an encroaching army of sentient machines that, in Acker’s hands, are the real show here — a cavalcade of gruesome droids with glowing red nerve centers and flailing metallic tentacles. Never as gripping in narrative terms as it is visually, 9 at its best exudes the feeling of a perversely fascinating ballet mécanique that literally expends with humans the way Hollywood blockbusters have been figuratively doing for years.