Fantastic Voyage - Plot

Plot

The United States and the Soviet Union have both developed technology that can miniaturize matter by shrinking individual atoms, but only for a limited amount of time, depending on how small the item is miniaturized.

Scientist Jan Benes, working behind the Iron Curtain, has figured out how to make the process work indefinitely. With the help of the CIA, he escapes to the West, but an attempted assassination leaves him comatose with a blood clot in his brain.

To save his life, agent Charles Grant (Stephen Boyd), pilot Captain Bill Owens (William Redfield), Dr. Michaels (Donald Pleasence), surgeon Dr. Peter Duval (Arthur Kennedy) and his assistant Cora Peterson (Raquel Welch) are placed aboard a specially designed submarine at the C.M.D.F. (Combined Miniaturized Deterrent Forces) facilities. The submarine, named the Proteus, is then miniaturized and injected into Benes. The ship is reduced to one micrometer, giving the team one hour to remove the clot. After 60 minutes the submarine will begin to revert to its normal size and become vulnerable to Benes' immune system.

The crew faces many obstacles during the mission. An arteriovenous fistula forces them to detour through the heart, where cardiac arrest must be induced to avoid turbulence, through the inner ear (all outside personnel have to remain silent to prevent turbulence) and replenish their supply of oxygen in the lungs. When the surgical laser needed to destroy the clot is damaged, it becomes obvious there is a saboteur on the mission. They cannibalize their radio to repair the device. When they finally reach the clot, there are only six minutes remaining to operate and then exit the body.

Before the mission, Grant was briefed that Duval was the prime suspect as a potential surgical assassin. But as the mission progresses, he pieces the evidence together and begins to suspect Michaels. During the critical phase of the operation, Dr. Michaels knocks Owens out and takes control of the Proteus while the rest of the crew is outside for the operation. Duval successfully removes the clot with the laser, but Michaels tries to crash the sub into the clot area to kill Benes. Grant fires the laser at the ship causing it to veer away and crash. Michaels is trapped in the wreckage and killed when white blood cells attack and destroy the Proteus. Grant saves Owens from the ship and they all swim desperately to one of the eyes where they escape via a teardrop seconds before they return to normal size.