If quirky bonding moments and revelations of terminal illness were the lone hallmarks of great filmmaking, “Around the Bend” would surely be hailed as the soaring melodramatic masterpiece of our time. If only. Instead, this earnest, twangy tale of fathers and sons must settle for a somewhat more modest accolade: mid-rent tear-jerker.

Josh Lucas — a ruggedly handsome 30-something actor in the Thomas Jane/Dominic West mold — plays Jason Lair, a single father who lives in Los Angeles with his ailing, yet jovial, grandpop, Henry (Michael Caine). Sensing that his last days are at hand, Henry happily contemplates the details of his funeral while proffering grandfatherly love and advice to Jason's plucky pre-pubescent son, Zach (7-year-old newcomer Jonah Bobo).

The three Lair boys are getting along just fine until the surprise arrival of Turner Lair (Christopher Walken), a recovering drug addict who has seen neither his father (Henry) nor son (Jason) in almost three decades.

Grizzled and contrite, Turner conceals a lifetime of secrets behind a pair of nervous, shifty eyes. Painful secrets, such as the reason he forfeited Jason to Henry's care all those years back. And the secret to Jason's pronounced limp, which has plagued him since childhood.

These secrets and more are unveiled when Zach, Jason and Turner hit the road for an encounter session-slash-scavenger hunt that sends them to New Mexico with lots of Henry- mandated pit stops at the old man's favorite restaurant, KFC. Unabashed product placement? Indubitably.
With every meal, the movie temporarily assumes the guise of a touchy-feely fast food ad: “KFC — a tasty and nutritious part of any bereavement process.”

Packed into a cramped camper van, the Lairs have mini-adventures involving unwanted funeral urns and neglected puppies that have a folky pleasantness about them, but also smack of sweetened artifice. The soundtrack is calculated for maximum masculine driftfulness, including cuts from Bob Dylan, Warren Zevon and — eek! — Leon Russell. What, no Gordon Lightfoot? Relegated to romantic sidedish roles (“Sweet Home Alabama”) and preppie villains (“The Hulk”) for most of his career, Lucas shines as Jason, the responsible father whose dredged-up abandonment issues have him teetering plausibly between outreach and bitterness.

And what can a mere mortal say about Caine (“The Cider House Rules”)? In a brief role, the one-time Cockney bad boy is money, exhibiting the curmudgeonly wit and feistiness that's become his specialty.

Ironically, it's Walken — that self- cranking emotive turbine — who seems most understimulated in “Around the Bend.” First-time filmmaker Roberts seems interested in Turner mainly as an instrument of closure and discards him just as arbitrarily. Worse, the director lets Walken (“The Deer Hunter”) indulge his ridiculous penchant for doing a little dance in all of his movies. Not only is it out of character for Turner, it unfairly recalls painful memories of Walken's performance in “America's Sweethearts.” Let's say it now: Mr. Walken, your jig is up.