A long lost trunk returned to the boys contains a tape recording of their deceased mother which brings to the surface a previously unrecognized problem that triggers uncharacteristic behavior from a usually happy-go-lucky Arnold.

To try to curb Arnold's run of bad luck, Drummond gives him a pet cricket, but the Japanese ""good luck charm"" brings nothing but sleepless nights and dreams of ""pesticide"" to the rest of the household.

A short visit to the United States by Phillip Drummond's Dutch cousin Anna and her son Hans becomes an eternity for Arnold and Willis, who are made scapegoats for cousin Hans' mischief.