- Illustrator: Hillar Mets
- Language: Estonian
- Tammerraamat
- 2018, 120 pp
- ISBN: 9789949616534
- fiction, storybook
- Age: 9+
A lot of time has passed since the young detectives Kribu and Krabu went on 3rd grade. By now Krabu a.k.a. Mati (91(, a retired police constable lives in a retirement home but old habits die hard as when his roommate Artur (87), ends up in a hospital with a suspicion of being poisoned, Mati doesn't think twice about it and gets right on track. Of course Piia (age unspecified but undoubtedly still quite young), jumps in to lend a helping hand.