|This article is about a/an episode in Engine Sentai Go-Onger.|
Basic Investigation (捜査ノキホン Sōsa no Kihon) is the third episode of Engine Sentai Go-Onger.
While Renn and Saki practice sparring with Gunpei, Sōsuke goofs around with Hant until Gunpei trips him. Gunpei criticizes the primary Go-ongers' childish antics until Bomper reports Gaiark activity at a mountain in nearby northern Kanto. Once there, the Go-ongers are shaken by a sudden tremor that takes out the forest before the gang get ambushed by the Ugatz. While the primary Go-ongers battle the Ugatz, Go-on Black and Go-on Green leave the fight and find the source of the tremor: Scoop Banki.
After being forced above ground, Scoop Banki overpowers the Go-ongers before escaping underground once more. Annoyed with the primary team, Gunpei takes Hant underground to further investigate Scoop Banki's activities. The two soon find Scoop Banki's set-up of a weapon of mass destruction. They charge in to fight Scoop Banki and destroy the weapon. However, Go-On Green and Go-On Black are defeated by an irate Scoop Banki and left for dead as he leaves to personally ensure his target's destruction.
Meanwhile, at Hellgailles Palace, Land Pollution Minister Yogostein reveals that Scoop Banki was initially incorrect about the target site, whose destruction would serve as Gaiark's declaration of war on the human race. The primary Go-ongers are hanging out at the Ginjiro-go and accidentally learn that Scoop Banki's target is the Neo Tokio Hills development, which is to open that day. At the ribbon-cutting ceremony, Scoop Banki arrives to wreak havoc, but is ambushed by Sōsuke, Renn, and Saki, who were in disguise at the event. Go-on Black and Go-on Green arrive, and the assembled Go-ongers then fight Scoop Banki, defeating him with the Bearrv-powered Highway Buster. Scoop Banki undergoes Industrial Revolution and Engine-Oh forms to fight him. Engine-Oh destroys Scoop Banki's shovel gauntlets before scrapping him.
After the battle, Bomper intercepts the energy signatures of the two new Engines entering Earth's atmosphere: Birca and Gunpherd.
- Go-On Red - Change Soul, Engine Soul #1
- Go-On Blue - Change Soul, Engine Soul #2
- Go-On Yellow - Change Soul, Engine Soul #3
- Go-On Green - Change Soul
- Go-On Black - Change Soul
- As part of Super Hero Time, this episode aired alongside Kamen Rider Kiva episode 6, Replay: Humans are All Music.
- Engine Eyecatch Race Winner: Engine Buson ("I'm doing great!")