Plot summary

This 1974 made for TV movie opens out in space. A rock tumbles on a collision course with Earth. The pulsating blue rock lands on an island off the east coast of Africa. It cools to a light rusty brown. The Warburton Oil Resources Company has a small construction crew on the island preparing the site for an oil exploration operation. Lloyd Kelly (Clint Walker) is driving a jeep to check on progress. He passes Chub Foster (Neville Brand), a maintenance mechanic pumping fuel into a pickup truck. He passes Dennis Holvig (Carl Betz) operating a large, orange Bucket Shovel. He stops near an idled Catepillar Grader. Beltran (James T. Watson Jr.) is sitting on the fender. Kelly asks, "What's the hang up, Beltran?" Seems the Grader needs the assistance of a D9 Bulldozer to get him up a hill but it hasn't shown up to assist. Kelly calls Mac on the radio, but there is no answer. McCarthy (Robert Urich) is with Dutch Krasner (James Wainwright) checking out an abandoned building. The island was a refueling station during World War II. The island is six square miles in size and two hundred miles off the coast of Africa. Kelly drives off in search of his missing man. Kelly finds McCarthy and Dutch rummaging through an abandoned locker. The crew has five days left to prepare a base camp for an oil drilling operation. McCarthy climbs aboard his Catepillar D9 Bulldozer. Kelly orders Dutch to go and help Beltran building the access road. McCarthy aims the D9 towards his objective and commands, "Ok, sweetheart, destroy." Title and credits roll over the demolition of the old Quonset hut by the Bulldozer. McCarthy gets off his rig to examine a metallic rock. He is unable to dislodge it. Kelly offers to show the younger man how to handle the Bulldozer. Mac hears a humming sound coming from the rock. Kelly gets a running start, but the rock won't budge. The rock begins to glow a bright electric blue, then transfers its energy into the blade of the D9. A flash of light knocks McCarthy to the ground. Kelly jumps off the D9 to assist the fallen man.In their tent that evening, Dutch, Dennis and Beltran discuss McCarthy's condition and Kelly's unreasonable push to complete work on the island. Kelly calls company headquarters on their radio for help. McCarthy lays on his cot, severely burned, his arm wrapped in bandages. Mac wants to talk to Kelly alone. The other men exit the tent, but Dennis holds back just outside. Mac asks, "Did you see it? I don't know exactly. When you hit the rock, blue. Whatever it was, you must have seen it." Kelly denies seeing anything. Struggling to breathe, Mac tells Kelly, "Blue light. It's there in the blade." Mac dies. Dennis, standing just outside the tent hears the entire exchange. Kelly informs Dutch and Beltran that Mac is dead and they will have to bury him temporarily. Kelly goes out to examine the Bulldozer. He climbs aboard and starts it. He is surprised when it seems to have a mind of its own. Unable to control the machine, he cuts a fuel line, but the D9 chases after him after he falls to the ground. Before it has a chance to crush Kelly, the D9 just stops. All except Kelly are present for an impromptu graveside service on the beach for Mac. Dutch was very close friend to Mac, and is especially angry with Kelly. He blames Kelly for Mac's death. Kelly drags the D9 back to camp using the Grader as a tow truck. Dennis tells the others that Kelly is a former alcoholic and this job is pretty much his last chance. Kelly was injured on the D9. In his tent he is talking to Chub while dressing the burn on his arm. He directs Chub to look over the D9 and tell him what was wrong with it. Dennis Holvig goes out for a cigarette next to the Bulldozer. The D9's headlights come on and the blade starts to slowly rise. The blade quickly drops startling Dennis.The next morning Kelly is back on the radio providing headquarters his daily status report. Chub is working on the D9 and outlines his findings to Kelly. Chub makes Kelly aware of the weird humming coming from the blade. Kelly goes into Dennis Holvig's tent to roust him back to work. Dennis wants to discuss the "blue light" first. Before Dennis leaves the tent he reports to Kelly, "Still last night I wondered. I could have sworn that D9 blade moved. It almost took my foot off." While Chub is working on the generator, Beltran boards the D9 and starts it up. Chub orders him off the D9, per Kelly's strict orders for no one to operate it. Beltran pretends not to hear the mechanic. Beltran drives off, then notices that the machine will not respond to command inputs. The wayward machine crushes the radio then heads off into the brush. Kelly gives chase in the jeep. The D9 continues through the brush despite Beltran's best efforts to control the mechanical beast. Beltran jumps off the D9. The bulldozer turns towards the man and chases him through the underbrush. Beltran crawls into a piece of loose galvanized drainage pipe, but the D9 rolls over it killing him. He is buried next to Mac, and then there were four.The four remaining men gather in Kelly's tent to talk while the D9 waits somewhere on the island to kill again. Dennis shaves while Dutch paces around in their tent. Dutch wants to go out for a midnight swim, but instead sits on his cot listening to music. Dennis goes outside and talks to Kelly. He asks exactly what happened to Beltran. Kelly replies, "The D9 was operating by itself when it ran him down - throttling, pivoting, floating the blade." Dennis slips out of the tent for a walk. It is dark now and he sees for himself the D9 prowling around. It flashes its headlights, then moves towards the man. Dennis runs back to camp and the D9 continues to plow under wood pilings.The next morning Kelly is having breakfast. He pours a cup of coffee when Dennis enters the kitchen tent. He flatly proclaims to Kelly, "I don't believe Mac was delirious. I saw the D9 operating all by itself. You saw it too, didn't you when it got Beltran?" Dennis hands Kelly a piece of the rock that started it all. Both agree it's a metallic meteorite. Dennis finally convinces Kelly the D9 must be destroyed. He suggests dynamite. Near camp, Chub and Dutch are refueling the Grader. Dutch tells Chub that they are both likely to join the other two buried near the beach. Kelly and Dennis pull up in the jeep and the four men witness the rogue D9 destroy their camp, tents and all. The four men head up to higher ground and watch the D9 systematically destroy everything in camp. The D9 sits out in the brush as the men survey the damage to camp. Dennis reports that there is enough canned food and water for a couple days - enough until the supply ship arrives in a few days. Dutch finally has his answer, "Remote control. That's got to be it. That thing is running by remote control." Dutch suggests to Kelly and Dennis that someone else must be on the island operating the D9. Kelly decides the four should head for higher ground. They take the two jeeps and the pickup truck. The D9 starts up and follows the men. The pickup truck can't make it up the grade. The men split up. Kelly and Chub explore the higher ground. From the top of the hill Kelly spots the D9 coming up a ravine. Kelly and Chub pile some kindling and douse it with gasoline. Their plan is to build a signal fire in hope of attracting a boat or airplane. They drive away after lighting the fire. Chub has an idea. He suggests ramming the pickup into the bulldozer. All the fuel barrels on the truck will catch fire and that should destroy any rubber parts and melt the electrical wiring. The D9 destroys the signal fire. The D9 ambushes the men. It destroys the pickup truck. Dutch was able to jump free, but Chub was unable to exit the truck before the D9 destroys it. And then there were three graves next to the beach. Dutch is convinced the D9 knew the plan. He tells Kelly, "It knew. That ambush. It knew what we were gonna do and it did it first." Both Dennis and Kelly think Dutch is losing it. The D9's next move is to plow a pile of rocks down on the men on the beach. One rock strikes Dennis. At the second rock fall the three men drive off in the orange jeep. The men wait in a ravine while the D9 lurks in the bushes. They can hear it, but they can't see the hellish thing. They decide to leave.That night Dutch paces back and forth nervously. He notes the sound of the surf. He returns to his midnight swim idea. He asks Dennis, "What's it doing out there?" To calm Dutch's frayed nerves, Kelly gives him a bottle of alcohol and suggests he take a nap. The next morning we see an empty liquor bottle and a very drunk Dutch. He drives the jeep off and proclaims, "I'm going swimming." He runs straight into the waiting D9. They face off in a sandy clearing. The D9 heads straight for Dutch, who naturally has trouble starting the jeep engine. The D9 quickly turns the jeep into a 6-inch thick pile of scrap. And then there were two. The D9 chases Kelly and Dennis, who are now on foot. They spot and then run to the Shovel. The D9 backs away to get a running start to attack the Shovel. The D9 jousts with the Shovel, skillfully operated by Dennis. It tries a couple of different angles, but the two machines seem evenly matched. Dennis gets the bucket under the bulldozer's blade, but the strain snaps a cable. The men run to the Grader. They finally deduce that the machine can't be killed, but the entity controlling it can be, but with what? In answer to the question how do you kill a killer, Dennis remarks, "It's too heavy to hang. It's too big to fit in a gas chamber." It is Kelly who suggests electricity - electrocution. They proceed to rig a trap using the generator and metal grating. They plan to use the Grader as bait to lure the D9 onto the grating, which is covered with brown tarps as camouflage. The D9 approaches Kelly, who is now sitting in the Grader. The D9 stops just short of the trap. The D9 turns to face the generator and Dennis standing behind it. Kelly grabs a crowbar and walks over to the monster and taunts it. A well-aimed throw of the crowbar takes out one of the headlights which infuriates the bulldozer. It makes straight for Kelly and right over the trap. Dennis throws the generator switch and fries the machine. It howls and thrashes and lifts and lowers the blade in its death throes. The blade turns a bright blue, then violet. The blade returns to normal color and the humming stops. It would appear to be dead and the two men cautiously approach the D9. Dennis suggests a plausible story to tell the company about the four men dying in a landslide, but Kelly insists on the truth - hard as it will be to explain or believe. Both agree they are glad to be alive. Kelly tosses his red hardhat up in the air. It lands on the D9. End Credits roll over a freeze frame of the D9 and Kelly's hardhat.