Continuity: Dr. Marvin tries out the new improved magnetic interference unit and invites Prof. Kanter to be the first one to shoot it. He walks over to Prof. Kanter standing in front of the gun twice between shots.

Plot hole: Carol and Dr. Marvin walk into The Internal Security Commission at The Pentagon and he's stopped by the guard and made to show his clearance. The guard looks at him intently but lets his wife in without any challenge or ID check.

Continuity: As Dr. Marvin tries out his high frequency ultrasonic gun in front of Maj. Huglin the engineer to the right of them turns on the generator. In the next shot the lighting has changed and the the shadow of Dr. Marvin's head appears on the pillar behind him.

Continuity: At the Pentagon Carol and Dr. Marvin speak to the generals and one of them holds a pipe in his right hand. In the next shot he's holding the pipe in both hands.

Continuity: After they've destroyed the alien craft spotted flying around inside of the Belmont lab, Dr. Marvin and the others decide to pack up and leave. Even though the sound has been edited out, the car and truck are already running with their headlights on before anyone gets into them.

Continuity: Carol and Dr. Marvin are locked in the underground bunker at "Operation Sky Hook" as the power goes totally dead. Somehow in total darkness without any power we still hear the sound of the aliens speaking which is strange because if you look at the tape recorder it's not running at all.

Continuity: Carol and Dr. Marvin are locked in an underground bunker at "Operation Sky Hook" and the doctor makes a tape recording of himself as the power goes out and the lights start to flicker. He says, "The batteries are failing, the recorder's not running up to speed" but if you look at the tape recorder it never slows down and keeps running at the same speed.

Continuity: After leaving The Pentagon, Dr. Marvin and Major Huglin arrive at the doctor's hotel in broad daylight. In the next shot as he walks in on Carol sleeping in their room, it's the middle of the night.

Continuity: At The Pentagon Internal Security Commission meeting a General asks, "Does anyone one want to have the recording played again?" and the two military officers standing in the back move to the left between shots, only to return several shots later.

Continuity: Dr. Marvin runs out of their hotel room and proceeds to his meeting with the aliens by the Chesapeake Bay. Carol calls Major Huglin in his room and we see that the filmmakers used the same room for both shots with items such as paintings, beds, lamps and water pitchers moved to different spots.

Other: As they travail to The Pentagon in Washington, Carol and Dr. Marvin sit in the exact same mock-up of an airplane's interior that we saw earlier in the movie when a UFO passes in front of it.

Continuity: There's no smoke inside of the alien spaceship but if you look closely before the motorcycle cop fires his gun, smoke from a previous take can be seen swirling above their heads.

Continuity: The alien's show a Navy Destroyer being destroyed by their death rays. Later as it explodes we see the remains of an aircraft carrier.

Revealing: When Carol, Dr. Marvin and the others enter the alien spaceship it's obvious by the sound that that they are walking on plywood made to look like metal.

Continuity: The alien's speak to Carol, Dr. Marvin and the others and show them a Navy Destroyer on their video screen firing on an alien spaceship. If you look closely the guns on the ship are not aimed at the alien spaceship.

Continuity: The motorcycle cop looks up at the alien's Infinitely Indexed Memory Bank and the front of his hair is combed up into a pompadour. In the previous shot it was combed down.

Continuity: The alien spaceship's shadow falls on the sand underneath where Carol, Dr. Marvin and the others are looking at it on the bank of the Chesapeake Bay. In the next shot as they all walk into it they're in sunlight.

Continuity: Carol's hair is parted in the middle as they stand and look at the alien spaceship as it sits on the bank of the Chesapeake Bay. When we see her inside the spaceship her hair is parted on the right.

Continuity: The Motorcycle cop that is taken up into the alien spaceship with them asks, "What team has won the most World Series?". When he asks the question he takes his hat off which leaves a dark impression on his forehead, in the next shot it's gone.

Continuity: As the alien's speak to them inside their spaceship, Dr. Marvin stands next to Carol. In the next shot from behind he has his arm around her waist.