The flick is full of thrills and spills – and plenty of amusingly lame jokes, says PEOPLE's critic

The magic is still there, only you have to work a little harder to make yourself believe this time.

Indiana Jones and the Kingdom of the Crystal Skull, the fourth chapter in the saga of the whip-wielding archaeologist-adventurer, is full of thrills, spills, chills and plenty of amusingly lame jokes. While the flick is easy to like, it never quite knocks you silly with delight the way 1981’s Raiders of the Lost Ark did.

Acknowledging that time has passed and its hero has aged, the movie is set in 1957 – 19 years after the last Jones film ended – at the height of the Cold War and the McCarthy era. Jones, we’re told, spent World War II working for the O.S.S. (the precursor to the C.I.A.) and earned himself a chestful of medals. The plot, as complex as ever, involves Russians as bad guys and sets Jones (Harrison Ford) on the trail of an ancient crystal skull that’s linked to a legend about Spanish conquistadors, hidden treasure, and supernatural powers.

After an early derring-do-filled brush on a New Mexico military base with the movie’s villain, Russian military scientist Irina Spalko (Cate Blanchett, using an accent worthy of Natasha in Rocky & Bullwinkle), Jones returns to his professorial duties at Marshall College. But he has barely doffed his dusty fedora before he’s heading to South America with his new sidekick, Mutt (Shia LaBeouf), a motorcycle-riding rebel who has clearly watched The Wild One too many times, adopting star Marlon Brando’s defiant attitude and greaser look.

Mutt needs Jones’ help to rescue his mother, who will – spoiler alert – turn out to be Jones’s long ago love, Marion Ravenwood (Karen Allen, reprising her role from the first Indy film). She has been kidnapped by Spalko, along with Jones’s onetime mentor (John Hurt). Soon, Jones is leading Mutt, Marion and other members of his posse through the jungle in the Amazon, over waterfalls, and inside ancient tombs and temples, battling Spalko all the way as everyone seeks the crystal skull.

Director Steven Spielberg, along with his cast, try a little too hard to recapture old times and the effort shows. In its uneven middle section, Skull huffs and puffs, like the now sometimes winded Jones.

The stunts are still impressive, the jokes funny (“No defiant last words?” Spalko asks Jones as she’s about to plug him. His sneering reply: “I like Ike.”) and the actors all fit comfortably into their roles and appear to be having a jolly enough time. But if you came to the movie cold, without a history of nearly three decades of familiarity with the characters (and a fondness for that stirring theme music), would the sight of Indy’s worn fedora give you such a warm, fuzzy feeling? Unlikely. Still, it is Indiana Jones and he won’t be around forever (Ford turns 66 in July) so, hey, it’s swell to have you back, Dr. Jones.