Martin Wide inherits a bus from his dying grandfather. He restores it from being a hen house into a tourist bus. He puts an ad in the newspaper about "travels to the sun" and also advertises for a stewardess at the same time. The female reporter Vera Boman signs up for the job, in order to expose the "tourist travel hoax". The two, together with passengers of various kinds set off from a snowy Sweden towards Paris. During the trip, Vera starts to realize that Martin is not a "tourist cheater" but a kind and thoughtful travel arranger, who tries to tend to all his passengers as best as he can, even when the situations become difficult to handle. In addition, a famous Swedish diamond has just been stolen and it turns out that both the thieves and the private detectives who are after them, are passengers on the bus.

Martin Wides morfar dör. I arv till Martin efterlämnar han en gammal buss som Martin rustar upp, förser med diverse egenhändigt tillverkade finesser och döper till Sommarpilen. Journalisten Vera Boman läser en annons i en tidning. Martin Wides turistbyrå söker en bussvärdinna. Hon rådgör med sin chef och beslutar söka platsen. Det här är ju ett utmärkt tillfälle att avslöja skojet i resebyråbranschen.