The Underground Mechanical Beast, Holzon V3

The Underground Mechanical Beast, Holzon V3 (地底機械獣 ホルゾンV3 Chitei Kikaijū Horuzon Bui Surī) is the 17th episode of Mazinger Z. This episode was first aired in Japan on March 25, 1973.

Summary
An massive earthquake ravages the city.

The Mazinger Team is discussing the disaster when Baron Ashura appears on TV. He not only claims responsability for the tremors, but also gives an ultimatum: the Japanese government must give Dr. Hell leadership over the Photon Power Laboratory or suffer with further earthquakes. While Koji and Sayaka are completely opposed to the idea, Dr. Yumi give it some thought.

Baron Ashura unleashes the Mechanical Beast responsible for the earthquakes, Holzon V3, once again. Its underground movements cause massive damage to the city just above it. As more people begin to die, Koji and Sayaka scramble to search for the Mechanical Beast. Meanwhile, a huge crowd protests in front of the National Diet Building. Shiro and Dr. Yumi watch on TV as the japanese people ask for Dr. Yumi's resignation. Baron Ashura makes a call to the Photon Power Laboratory demanding japanium to be surrended to him in the next dawn.

Dr. Nossori and Dr. Morimori are sent to collect the metal from the lab's safe, Nossori has a different idea. They bring the case containing the metal to Koji who goes to meet Baron Ashura at the designed spot

In exchange for japanium, Koji wants Holzon V3. Ashura agrees, but asks to given the metal first. After acquiring the metal, he asks Koji to follow him. However, they are intercepted by Aphrodite A. Sayaka refuses to let him escape with the source of photonic energy and tries to capture Ashura. Ashura summons an army of Iron Masks and escapes during the comotion.

Ashura returns triumphant to Bardos and presents Dr. Hell with the miraculous metal. After opening the case, Hell quickly realizes they have been duped: the alloy given to Ashura was fake. Furious, Baron Ashura leads an attack to the lab. In exchange for Japan's safety, Ashura demands to be given control over the Photon Power Laboratory. Dr. Yumi and the others hatch a plan to deal with Holzon V3, but first they need to bring it closer to the lab. Gennosuke, Koji and Sayaka leave the laboratory only to refuse Baron Ashura's proposal to his face. This prompts him to summon Holzon V3.

When the Mechanical Beast enters the Photon Power Laboratory range, the scientists send surge of photonic energy underground. This causes stuns Holzon V3 and brings it to the surface. Mazinge Z and Aphrodite A deploy.

Mazinger Z destroys Holzon V3 putting an end to the earthquake attacks.

Recurring

 * Koji Kabuto
 * Sayaka Yumi
 * Shiro Kabuto
 * Gennosuke Yumi
 * Three Scientists
 * Dr. Hell
 * Baron Ashura

Machines

 * Mazinger Z
 * Hover Pilder
 * Holzon V3

Weapons

 * Aphrodite A
 * Oppai Missile
 * Mazinger Z
 * Rust Hurricane
 * Rocket Punch