Jonny Quest Wiki
Jonny Quest Wiki

The Invisible Monster is the twentieth episode of the 1960's Jonny Quest.


A laboratory experiment accidentally creates a monster, which is not only made of pure electricity, but also invisible, which goes on an explosive rampage.


On the South Pacific grounds of Cave Island, Dr. Isaaha Norman (an elder American scientist) works late into the night in his Quonset hut laboratory. With powerful generating equipment, he is conducting experiments into high-energy molecular physics. The generators overload, however, and the tin building is rocked by a huge explosion. The unconscious Dr. Norman comes to in the ruins of his lab, just in time to glimpse a quivering blob of light escaping through a jagged rent in the wall. Outside, there is a strange electronic wailing sound as smoldering footprints appear spontaneously along the ground. They advance across the laboratory compound, blast their way through a high cyclone fence, and continue off into the jungle, bursting every tree in their path into splinters.

Halfway around the world, it is daylight at the Quest family home on Palm Key, Florida. Bodyguard, Race Bannon, receives an emergency transmission over the shortwave radio and alerts his employer, the eminent American scientist, Dr. Benton Quest. It is Dr. Norman calling for help from Cave Island. Even as he tries to explain what has happened, the old Doctor's creation returns and consumes him... making him disappear in a bizarre flash of anti-light (resembling a negative camera image). Dr. Quest hears the whole incident over the radio.

Outside on the beach, Dr. Quest's son Jonny and his adopted Indian son, Hadji, are sunbathing with their pet bulldog, Bandit, when the shadow of a Quest hovercraft falls over them. It is Race, calling the boys in to get ready for a trip to Cave Island.

In a nearby native village, a skinny dog senses the approach of some unnatural force and cowers under the stilts of a bamboo hut, whimpering. A young Polynesian man comes to the door of the shack to see what all the commotion is about...only to disappear the same way Isaiah suffered.

Soon, the entire party takes off in the Quest vertijet (a Harrier-like VSTOL aircraft).

After a long night's flying, the Quest party finally arrives over tropical Cave Island.

Upon vertical landing at Dr, Norman's lab, the Quest party finds the entire compound in a wrecked shambles. Dr. Quest begins to pour over Dr. Norman's notes to determine what has happened, when Jonny discovers the mysterious scorched footprints leading off into the jungle. He, Race and Hadji decide to investigate by rocket belt while the Doctor continues to examine the lab for evidence.

Flying overhead, the trio is easily able to follow the trail of destruction through the jungle to the wrecked native village. From their high vantage point, they see another village - and the path of destruction is working its way through the trees straight toward it! Clearing its way like a bulldozer, the source of the destruction finally emerges into the reveal that it is invisible! The smoldering footprints, however, continue toward the native village.

Race, Jonny and Hadji land to warn the villagers, only to find the place already abandoned - but the invisible monster is approaching, still! Race fires his rifle into the oncoming footprints, but to no effect. There is only a strange electronic wail, like horrible music from a theremin synthesizer. Race and Jonny take to the air, but there is a problem with Hadji's rocket belt...and the footprints are almost upon him! Without a moment to lose, Race and Jonny swoop down and pluck the stranded boy out of harm's way.

The trio returns to the lab compound, where Dr. Quest has pieced the situation together from Dr, Norman's notes. They are dealing with an invisible energy monster who lives only to feed - and feeds on any kind of energy (from solar power and electricity, to the calories in a living body). To fight the thing, they must first find a way to make it visible - so Jonny suggests that they paint it. The idea makes sense and Race is soon off to the compound's supply locker to make paint bombs out of plastic bags. Hadji, meanwhile, must tend to his faulty rocket belt.

The entire Quest party is soon airborne by rocket belt, tracking the monster (again, by its path of destruction). They eventually catch up to the creature, judge it's position by the progression of it's footprints, and pelt it with their paint bombs. Amid much wailing and electrical arcing, the invisible thing begins to take shape. Covered with florescent dye, it is revealed as a bobbing, ghost-like glob with one cyclops eye and a gaping black hole of a mouth (resembling something out of Pac-Man). The monster is headed back towards the lab compound and Dr. Quest reasons that it will be looking for electrical power once the sun goes down. They race the creature back on their rocket belts.

Back at the compound, the Quest party works feverishly to prepare a trap for the monster. The Doctor believes he can use some salvaged lab equipment to reverse-engineer the process that created the thing. The others employ a Quest hovercraft to string a network of light bulbs among the trees and connect them to a switchboard in a bamboo hut on the compound. The work is finished just in time.

As night begins to fall, the creature arrives on the outskirts of the compound. With Race, Jonny and Hadji ensconced in the bamboo hut, Dr. Quest rocket belts off to his position in the cave which gives the island its name. Bandit tries to follow him, but gets caught out in the open, just as the monster arrives on the scene. the terrified little dog buries his head in the sand as the creature approaches to devour him. Ignoring his bodyguard's orders, Jonny rushes out of the hut to scoop Bandit up and carry him back to safety...just in time to save him! Race operates the switchboard to activate the the series of light bulbs, which draw the electricity-seeking monster toward the cave entrance. There, Dr. Quest uses a flashlight to lure the creature into the back of the cave, where the reverse-engineered lab equipment is waiting. Once the monster reaches the target point, the Doctor activates the apparatus and the screaming monster is caught in an energy draining field. Amid much flashing and arcing, the creature is instantly whittled away to nothing.

When it's all over, Jonny and Hadji try to cure Bandit's fear of monsters, by standing on one another's shoulders and donning a sheet to look like a tall ghost. But the little dog doesn't fall for the ruse. Bowling the boys over with a joyful leap, he practically smothers them in a frenzy of face licking.

That evening, the Quest party takes off in their verti-jet and leaves Cave Island behind. Dr. Quest laments the many setbacks that occur in the field of science - even as he vows to continue in its pursuit.



Main characters:

Supporting characters:

  • None


Other characters:




  • Hovercraft
  • Plane


Tim Matthieson Jonny Quest
Don Messick Dr. Benton Quest
Mike Road Race Bannon
Danny Bravo Hadji
John Stephenson Dr. Isaiah Norman


  • This episode is adapted into Comico's Jonny Quest #30. Changes include:
  • It's done in the form of a story being told to Dr. Quest's girlfriend.
  • Cave Island is renamed Cape Island.


  • Dr. Quest appears on Race's portable communicator, even though he was only wearing a headset.
  • Incorrectly regarded as goofs: While 'consume' can be a synonym for eating, Dr. Quest meant it in the scientific sense, to "use up". The monster does not eat and digest like an animal, rather, it completely converts its target's total mass into pure energy and absorbs it, leaving no residue or remains; hence, consuming things. (How it does this without releasing that energy as a nuclear explosion is left as an exercise to the scientifically curious viewer.)

Home media




External links

  • Buy this episode from Amazon, either in the US or UK
  • Buy this episode from iTunes, either in the US or UK