The franchise's third entry captures our hero's spiritual quest, an integral part of the beloved series.

“Indiana Jones and the Last Crusade” is one of the great summer movies an adventure that continues to delight and inspire audiences of all ages.

Director Steven Spielberg’s 1989 film, which turns 30 May 24, was noted during its release for seeming “gentle.” That description appeared in many film reviews (even the positive ones).

It seems appropriate, especially in light of the prior Indiana Jones adventures, “Raiders of the Lost Ark” (1981) and “Indiana Jones and the Temple of Doom” (1984). The latter was an exceptionally dark film (especially considering Spielberg’s family-friendly reputation at the time), with its scenes of child abuse, demonic sacrifices and nausea-inducing cuisine.

Reports that audiences were traumatized by the violent, Spielberg-produced “Gremlins” and “Temple of “Doom,” both rated PG (and released during the same summer) resulted in the creation of the much-needed, middle of the road PG-13 rating by the MPAA.

Oddly enough, “The Last Crusade” is the lightest of the trilogy (I’ll refer to it that way not to criticize what came after but to maintain focus) and seems undeserving of the PG-13 rating its filmmaker unintentionally created.

More intriguing, the film pushes forward the plot motif that the prior films have utilized: archaeologist Dr. Henry “Indiana” Jones pursues an object with supernatural history and, in the end, must “believe” in order to survive.

For all the deserved acclaim these films have garnered for being brilliantly produced recreations of ’30s adventure serials and among the greatest action movies ever made, they are all about the need to embrace the notion of faith.

The opening scenes establish the character of Indiana Jones so well, audiences new to the series won’t be at all lost. As a boy, we see Jones played by River Phoenix, in a performance that, while brief, offers further proof that he was among the best young actors of his generation.

Phoenix isn’t merely doing an impression of leading man Harrison Ford, he clearly gets the character. Watching his facial expressions closely during the wonderful prologue is as enjoyable as the sequence itself.

When the story briefly (very briefly) slows down, we see Indiana take on the guise of college professor Dr. Jones (yes, it is his Clark Kent-like costume, complete with glasses and a relaxed vocalization that eclipses the obsessed adventurer).

These scenes acknowledge what we’ve always suspected about Dr. Jones – he’s a terrible teacher. His exasperated assistant notes he has a stack of ungraded term papers and, after announcing he’ll be in his office for 90 minutes, Jones flees the campus.

Once the film’s supernatural totem is established (here, it’s the Holy Grail), Jones’ mentor and friend, Marcus Brody (the late, great Denholm Elliot) warns him (as he did in the first film, regarding the Ark of the Covenant) of the great danger involved with searching for the Grail.

Adding dramatic fire is Jones’ realization that he will also have to find his father, Dr. Henry Jones Sr. (played by Sean Connery), but let’s focus on a key moment in this exchange. Jones stares at his father’s paintings of religious imagery and asks, “Do you believe, Marcus?”

His friend’s response: “The search for the cup of Christ is the search for the divine in all of us.”

Spielberg has admitted on occasion that his “E.T. The Extra-Terrestrial” was an unintentional re-telling/modernization of the story of Christ. “E.T.” is a secular film about Jesus Christ and Christian faith but not this one.

With “The Last Crusade,” it’s all out in the open.

The story makes a stop at Venice (“Ah, Venice”) and into the tomb of Crusader Sir Richard (Connery wound up playing that role a few years later in “Robin Hood: Prince of Thieves”), before we finally get Henry Jones Jr. and Sr. together.

FAST FACT: “Indiana Jones and the Last Crusade” came in second at the U.S. box office in 1989 ($197 million), behind Tim Burton’s “Batman” ($251 million).

A nice realization comes even before the father/son comedy duo carries the rest of the film: “Indiana Jones and the Last Crusade” is really funny. Spielberg has never had true success with comedy before, as his dreadful “1941” and the Keystone Cops-leaning bits in “Temple of Doom” (and even the destroy-the-lawn sequence from “Close Encounters of the Third Kind”) are overdone and heavy-handed.

In “The Last Crusade,” there’s lots of slapstick, Blake Edwards-worthy verbal and visual wit and elaborate pratfalls. It all works.

At the mid-point, Jones Jr. and Sr. are in a motorcycle pursuit from the Nazis (“Nazis…I hate these guys”). The younger Jones spectacularly thwarts their pursuers and celebrates the moment. Indiana is thrilled and turns to his disproving father who, riding along in a side car, frowns and winds his watch.

This is Spielberg’s best comedy.

For large patches of the film, it’s just Ford and Connery, who tap into that elusive Butch and Sundance-level of comic potency and genuine chemistry that eludes so many high concept film pairings. Ford has always been terrific in this role but seeing Indiana have to literally deal with his daddy issues on the go is a riot and surprisingly touching.

Connery is excellent, finding joy in a nerdy bookworm who learns to embrace the constant danger. It’s Connery’s performance in this movie, and not “The Untouchables,” that should have won him an Oscar.

Once Ford and Connery take the wheel for the entire second act and make this a two-hander, we’re in movie heaven. The pairing of Han Solo and James Bond sounded novel when it was first announced in 1988, but it’s so much better than that.

These two actors visibly like one another and their sense of play and timing is rich in every sequence. Note how they escape captivity using a Zippo lighter – Spielberg’s crack timing and the unabashed hamming it up from Ford and Connery make it a tour de force.

So is the more serious give and take between the actors on a Zeppelin, as the characters express how their shared stubborn natures have cost them a genuine relationship.

The loss of a father figure is central theme for numerous Spielberg films – from “Jaws” to “Catch Me If You Can” and “War of the Worlds,” to name a few. Because “The Last Crusade” is a comedy, the subject goes down easily but there are still dramatic moments that sneak up on you (like a cleverly staged bit where Indiana is believed to be dead).

After a large scale Nazi book burning that Spielberg makes both scary and funny (you sense Spielberg was whistling “Springtime For Hitler” as he shot this), the Joneses go up against the Nazis and a massive tank.

The action sequences get increasingly larger in scale but the emphasis is always on character, which makes each set piece suspenseful and never losing its human center.

Despite his acumen as a scholar and archaeologist (though he pulls a thigh off a skeleton at one point and douses it with kerosene – so much for respecting the dead), Jones’s willingness to believe in a higher power is the characteristic that saves him the most in this and the prior movies.

“The Last Crusade” gets downright surreal in the final stretch, in which Indiana’s faith is literally tested.
The plot follows the “Raiders” template without ripping it off, finding enough innovation to enrich both the action and the choice character moments (“I was the next man”).

Intriguingly, “Indiana Jones and the Last Crusade” was released by the same studio (during the same summer, no less) that distributed William Shatner’s directorial debut, the widely dismissed “Star Trek V: The Final Frontier.”

Shatner’s ambitious, fatally uneven but better-than-remembered sci-fi fantasy also explores (to far less success) the relationship between faith and hard science. Or, as Dr. Jones lectures his students, fact versus truth”…and X never, ever marks the spot.”

Until, a few scenes later, when it does.

By contrasting what is believed and the unknowable, both of the Joneses have spent their life believing in something greater than both of them, respecting traditions and lore without fully committing to true belief.

By the film’s end, they have faith and their ability to believe is what unites them profoundly.

If anything ever bothered me about “Indiana Jones and the Last Crusade,” it’s the character of Elsa, played by Allison Doody. The actress is especially good in the role, particularly during the first half, when she hides a big secret. Later (SPOILER ALERT FOR A 30-YEAR OLD MOVIE EVERYONE AND THEIR GRANDMOTHER HAS SEEN), Elsa is revealed to be a sympathizer and supporter of the Nazi party.

Elsa’s disdain during the big book burning set piece is ill-defined and so is her change of heart in the final stretch. While her secular view towards the Holy Grail/lack of faith is made into a lesson by Jones Sr., the way the film ultimately deals with her feels wrong.

Whether she lives or dies at the end, it feels like a cheat and an easy way out to deal with a morally complex character. Marion Ravenwood and Willie Scott never had it so bad.

If “Raiders of the Lost Ark” is an American James Bond and “Temple of Doom” is “Gunga Din,” then perhaps “The Last Crusade” is “Don Quixote” in reverse, with Jones Jr. acting as Sancho Panza to the elderly visionary and mentor that is Jones Sr.?

A final word: I’ll address the unfairly maligned but often captivating “Indiana Jones and the Kingdom of the Crystal Skull” in this way: there’s a scene in that 2008 film in which Indiana is being chased by a horde of warriors. Running alongside him are Marion Ravenwood, Mutt Lang…John Hurt, Ray Winstone and I can’t remember who else.

The point is, it’s too much.

That moment always summed up my problem with that film – its cluttered. The key joy to “Indiana Jones and the Last Crusade” is that, for the most part, it’s about just two people: a father and son, discovering what it is they believe, about life, God and one another.

Is there a greater adventure than that.