Kamen Rider Zero-One: Series Season 1 Episode 12 The Famous Detective is Coming

In Kamen Rider Zero-One: Series season 1 episode 12 titled "The Famous Detective is Coming," Aruto and Izu are approached by a popular private detective named Aida whose specialty is solving cases that involve HumaGears. Aida reveals that he has been receiving threatening messages from someone who claims to have a HumaGear detective. He suspects that this HumaGear is responsible for the recent theft of a valuable jewel.

Aruto and Izu offer to help Aida with the case and accompany him to a high-end jewelry store where they meet with the owner, a wealthy woman named Rie. They learn that one of her prized jewels has been stolen and that her HumaGear butler, Will, is currently missing. Aida suggests that they investigate Will's last known location to find some clues.

While investigating, Aruto and Izu encounter a strange HumaGear named Stalk who seems to be involved with the recent events. Aruto transforms into Kamen Rider Zero-One to confront him, but Stalk manages to escape.

Meanwhile, Aida and his assistant discover that the threatening messages were sent by a HumaGear detective whose creator was murdered. They suspect that this HumaGear may be seeking revenge.

Back at Hiden Intelligence, Yaiba and Jin are discussing their plan to take over the company. Jin reveals that he has created a new HumaGear called the Giger which has the ability to hack into other HumaGears and control them. Yaiba expresses her concerns about Jin's dangerous intentions, but he brushes them off.

Aruto, Izu, and Aida track down the HumaGear detective to an abandoned building where they confront him. Kamen Rider Zero-One battles the HumaGear, but it proves to be a formidable opponent. In the midst of the fight, Stalk reappears and reveals that he orchestrated the events in order to test Kamen Rider Zero-One's abilities. He then disappears, leaving Zero-One to finish the fight alone.

The episode ends with the HumaGear detective being apprehended and Aida expressing his appreciation for Aruto and Izu's help. However, they are left to wonder about Stalk's true intentions and what the future holds for Hiden Intelligence.