Invasion of Astro-Monster [Godzilla vs. Monster Zero] (1965) Review| Godzilla Island Archive

The Plot:

A planet named Planet X is discovered by the World Space Authority, and two astronauts are sent to investigate. When they arrive, they see strange lightning in the sky and soon realize they are not alone. The astronauts are taken underground by the Xiliens, the inhabitants of Planet X.

The Xiliens explain that their world was once like Earth until it was devastated by Monster Zero. During the explanation, the base is attacked by Monster Zero revealed to be King Ghidorah. The Xiliens, who name everything by numbers, have been struggling against Ghidorah for survival.

After repelling the attack, the Xiliens propose a deal: in exchange for Godzilla and Rodan (whom they call Monsters One and Two), they will give humanity the secret to curing all disease. They want the two Earth kaiju to defeat Ghidorah so they can reclaim their planet’s surface.

The astronauts reveal they don’t know where Godzilla and Rodan are, but the Xiliens inform them they’ve been monitoring Earth: Godzilla sleeps at the bottom of Lake Myojin, while Rodan rests in Washigasawa. Returning to Earth, the astronauts share the proposal, and humanity is thrilled at the possibility of curing disease.

The military quickly locates Godzilla in Lake Myojin. As they investigate, a flying saucer rises from the water, revealing the Xiliens were already operating on Earth. They evade explaining their secrecy, then lift Godzilla from the lake and transport both him and Rodan back to Planet X. The astronauts join them, eager for the promised cure.

On Planet X, the Xiliens waste no time unleashing Godzilla and Rodan against Ghidorah. Controlling the kaiju with magnetism, they watch as Godzilla and Rodan force Ghidorah to retreat once again. True to their word, the Xiliens give the astronauts a tape containing “disease research” and send them back to Earth.

But when Earth scientists play the tape, they discover no cure—only a warning: the Xiliens will invade Earth using Godzilla, Rodan, and Ghidorah. Panic sets in. Remembering the Xiliens’ reliance on magnetism, Earth’s defenders develop a counter-weapon to break their control.

One astronaut’s girlfriend, revealed to be an undercover Xilien, defects and shares a secret weakness: a specific sound frequency that cripples Xilien technology. The frequency is broadcast across Japan, disrupting the invaders’ control. Godzilla and Rodan are freed and immediately turn against Ghidorah.

As chaos spreads, Xilien ships malfunction and explode. Godzilla and Rodan double-team Ghidorah, tackling him off a cliff into the sea. Ghidorah rises and flees back into space, but Godzilla and Rodan never resurface. While some believe they survived, doubt lingers. In the end, one astronaut is ordered back to Planet X implying humanity isn’t finished with the Xiliens.

My Thoughts:

Released just one year after Ghidorah, The Three-Headed Monster (1964), this film acts as a direct follow-up. Personally, I enjoyed this story much more than Ghidorah’s first appearance.

One question I had was: why didn’t the Xiliens want Mothra? My guess is they assumed Mothra wouldn’t leave Earth or would be harder to control. But leaving Mothra out had an interesting effect it let Rodan and Godzilla stand on their own as defenders, without Mothra acting as the “moral compass” like in the previous film.

That said, the Xiliens made some questionable choices. Why openly admit they control monsters with magnetism? Why not attempt the same with Ghidorah? If they hadn’t revealed that weakness, humanity might never have broken their control. Also, why bother making contact in the first place? With their technology, they could’ve simply taken Godzilla and Rodan secretly and attacked Earth immediately.

Strategic flaws aside, I have very few complaints. In fact, this is my favorite of the first three color Godzilla films. The story is engaging, the characters are fun, and the kaiju action delivers. For me, Ghidorah will always be Godzilla’s greatest enemy, and this movie solidifies why.