Dink got five blue envelopes from O. Bird, Doris’s Mother. The zip code was right, but the abbreviation of State was wrong. CO was for Colorado, and CT was for Connecticut.
Doris came to get the envelopes. These letters were from her mother who died last month. However, the envelopes disappeared.
The children found some clues. Doris said her mother was called Bessie Duncan and died last month. The name on the return address was O. Bird, and the letters were written last week. And then they found some pinholes through the letters H, D, J, O, F, and E.
Further, they found pinholes on the words: Jenny, hid, den, on, fifth, envelope. (Jenny hidden on fifth envelope.) There were three stamps on the fifth envelope, and something dark was under those stamps.
Ruth Rose steamed the stamp off the envelope. It was a stamp with picture of upside-down airplane. They went to the library to search some information of the stamp. Stamps that were printed upside down by mistake were called invents. And then they knew the name of the stamp was CURTIS JENNY SINGLE-ENGINE AIRPLANE, and it worthed 50,000 dollars.
The children knew that O. Bird and Doris Duncan stole the stamp. So, they decided to return the letters without the Jenny stamp and told the whole story to Officer Fallon.
The man with Doris Duncan chased after the children. But the children hid in the hay and loft. And then the children with Officer Fallon planned to trick the jerks.
Ruth Rose traded with the two jerks, and then the two jerks were under arrest for theft and mail fraud.