Rider Woofson is the leader of the P.I. Pack, who investigates crimes.

Westie Barker, a member of the P.I. Pack,  is testing to earn his yellow belt at Pawston Martial Arts Dojo in Bark-Jitsu. Westie is unsuccessful at each stage of the trial, but the next student, a cat, succeeds easily. After the night of testing, Sensei Hiro sets the high-tech security system on his way out of the dojo. Then, Sensei Hiro hears a noise outside. He looks into a store window. “Suddenly a scary face popped into view. It had a huge hairy nose, pointy ears, green skin, and large red eyes. ‘Oh no!’ Sensei Hiro cried out. ‘It cannot be! The ancient Goji Goblin has come for the sacred Scroll of Bark-Jitsu!’   ” (24-25)

Sensei Hiro seeks out the help of his student, Westie, and the rest of the P.I. Pack to protect the ancient scroll, which the Goji Goblin has been after for generations.

Mr. Meow, the P.I. Pack nemesis, has cat burglar ninjas breaking into the dojo to steal the scroll. Mr. Meow has arranged to have the P.I. Pack, who are on stake-out at the dojo, taken into the police station for questioning while the cat ninjis are at work. Westie, the Pack’s inventor, is able to stop the ninjis. Then, Gus dressed up as the Goji Goblin enters. Westie takes off with the scroll heading towards the police station. The rest of the P.I. Pack emerge from their police questioning just in time to catch Gus.

” ‘Westie, my student,’ Sensei Hiro said. ‘You were very brave in the face of great danger. You protected the Scroll of Bark-Jitsu and stopped the bad guys. To accomplish such a feat, you must have a pure and brave heart. For that you deserve this…’ The sensei pulled out the yellow belt.” (113-114)

Across town, Mr. Meow is not happy that P.I. Pack has ruined his plans again.

Gray-tone pencil pictures are on almost every page.