LAUGHLIN: Tell me something: What the hell is happening here?
PROJECT LEADER: It's Flight number 19.
LAUGHLIN: 19 what?
PROJECT LEADER: It's that training mission from the station at Fort Lauderdale. They were doing target runs.
LAUGHLIN: Who flies crates like these anymore?
PROJECT LEADER: No one. These planes were reported missing in 1945.
LAUGHLIN: But it looks brand new. Where's the pilot? I don't understand. Where's the crew? Hey! How the hell did it get here?
Close Encounters opens with a mystery and a guy asking a boatload of questions. Of course, that's the whole point. Lacombe and Laughlin wouldn't need to search for knowledge, and Spielberg wouldn't have a movie, if they had all the answers to begin with.
ROY: Help! I'm lost. [Speaking to his maps.] You'll cough up a little Tolono, right? Tolono on Interstate Highway 90, a little familiar landmark of some sort… Cornbread? Working?
[Waves car past.]
PASSENGER: You're in the middle of the road, jackass!
ROY: Could you tell me where Cornbread is? Turkey!
Roy getting literally lost early in the film is a setup for the more serious disorientation he's about to experience shortly. His maps aren't much of a help in his truck, but there are definitely no guidelines for understanding what's going to happen next.
LAUGHLIN: Excuse me. Excuse me. Before I got paid to speak French, I used to read maps. This first number is a longitude. Yeah. Two sets of three numbers: degrees, minutes and seconds. And the first number has three digits and the last two are below 60. Obviously, it's not in the right ascension and declination on the sky. These have to be Earth coordinates.
Notice how Lacombe isn't solving the problem like some kind of super Sherlock genius. Instead, the film takes a more realistic approach: that is, the skills, knowledge and intelligence of several people come together to solve the problem. In this scene, it's Laughlin's cartography knowledge that put the pieces together but it's the researchers and technicians that got him the necessary information to interpret. It takes a village to understand aliens.
ROY: Hold it, hold it, hold it! Is that it? Is that all you're gonna ask me? Well, I've got a couple of thousand God-damned questions, you know? I want to speak to someone in charge! I want to lodge a complaint. You have no right to make people crazy. Do you think I investigate every Walter Cronkite story there is? Huh? If this is just nerve gas, how come I know everything in such detail? I've never been here before. How come I know so much? What the hell is going on around here? Who the hell are you people?
Roy continues to seek answers from people in authority, answers Lacombe and Laughlin can't provide. Like with the map earlier, Roy remains in the dark, but he senses that the authorities want it that way. There's disinformation flying everywhere.
LACOMBE: Monsieur Neary, what do you want?
ROY: [Sighs.] I just want to know that it's really happening.
Roy finds a piece of the knowledge he's sought—that the UFOs and aliens do exist and he's not crazy. But everything else is still a mystery. In his final scene, Roy boards the mother ship as part of project Mayflower and enters a place beyond human understanding. Lacombe says to him, "I envy you." So do we.
[Lacombe teaches the alien the hand signs for the 5-tonal phrase. The alien mirrors the hand motions, and the two smile at one another.]
We probably have the most to learn from the aliens—like how to build those cool spaceships and travel at speeds faster than light—but Lacombe shows that we can also teach them. The alien's smile suggests they're willing to learn, too. That's how they got all that awesome gear. The film's message is that the search for knowledge benefits everybody.