As Wolverine, the unstoppable mutant with the shiny metal knuckle knives, Jackman artfully embodies a character who is both ferocious and humane. In this fourth X-Men installment, we learn how Wolverine is recruited into a secret military corps and lured into the sinister Weapon X program.

Jackman invests his fierce character with a cheeky attitude, clear-eyed intelligence and inherent decency, compelling viewers to care about his metamorphosis.

Wolverine, set circa mid-1970s, also reveals the early years of the vicious Sabretooth (Liev Schreiber) and the villainous William Stryker (Danny Huston).

A few mutants are unveiled: Deadpool, a wise-cracking swordsman with deadly aim (Ryan Reynolds); Gambit (Taylor Kitsch), who can imbue inanimate objects with explosive charges; and the teleporting Wraith (The Black Eyed Peas' Will.i.am).

Despite a couple of "Nooooo" yowls, Wolverine is well-acted, with spectacular action and witty one-liners. The special effects are top-notch. A few plot points raise questions, such as how Wolverine lost his memory. And his romance with Kayla Silverfox (Lynn Collins) is unconvincing.

Some sequences stand out: A scene with a helicopter, a tank and several Hummers in pursuit of Wolverine is exhilarating. Equally spectacular is a climactic fight on the edge of a nuclear reactor.

Though consistent in tone with the previous movies, this prequel, directed by Gavin Hood (2005's foreign-language Oscar winner Tsotsi), is an otherworldly fantasy, where the others were dark and brooding sci-fi adventures.

Although it's a quintessential popcorn movie, Wolverine is not mindless. Hood and Jackman bring depth to a comic-book tale of anti-heroes with anger issues.