Cool Shock B.T. - Chapter 5
The Dinosaur Fossil Thief Incident (恐竜化石泥棒事件 Kyōryū Kaseki Dorobō Jiken) is the fifth chapter of Cool Shock B.T.. The chapter was originally published in WSJ in three parts as the sixth, seventh, and eighth chapters of the series.
One day, B.T. and Koichi infiltrate a museum at night. It is revealed that Koichi has paid a visit to B.T.'s home, meeting an unknown woman on the way. More importantly, B.T. learns about and plans to steal the skull of a spinosaurus whose skeleton is being exposed at the museum. B.T. and Koichi enter the museum during the day and break into a storage room. A guard named Saiko catches Koichi, but B.T. distract him, allowing the kids to hide in a crate. In the process of stealing the skull, the boys trigger an alarm and Saiko comes to catch them.
B.T. sprays Saiko with a fire extinguisher to blind him, allowing the boys to run away. On their way to the exit, the boys cross path with the woman from earlier, but their interrogations are cut short when the woman goes away without explaining herself. B.T. and Koichi try to take an elevator but several guards come out of it. B.T. and Koichi nonetheless manage to enter the elevator without being caught, but are intercepted by Saiko. As a final ploy, B.T. bluffs Saiko into believing the stuff from the fire extinguisher and a hairspray will chemically react to create acid, and the guard is intimidated into letting the boys go.
The next day, B.T. confronts his grandmother about last night and she reveals that she manipulated B.T.'s fascination with fossils to goad him into stealing the skull. The ensuing chaos would then let her own agent, the woman, go into a safe room and steal the jewels stored there. B.T. can only acknowledge his grandmother's mastery, although he later tells Koichi that he did snatch a few jewels from the deposit point of the treasure by using Saiko's keys.