Mysterious holes in the ground appear during the night, causing Oliver's bicycle to be destroyed. Who made these holes and why? The child detectives Tiril and Oliver will have to be as smart as Sherlock Holmes to find out.
1939
2014
2013
2009
1991
1940
2022
2000
2006
1973
2016
2017
1943
2023
2020
2024
1983
2007
