Thomson and Thompson first appeared in "Tintin in the Congo", making only a brief one-panel appearance; their first appearance towards the plot of a story was in 1932, in "Cigars of the Pharaoh", when they come into conflict with Tintin on board a ship where he and Snowy are enjoying a holiday cruise. When this adventure was first published they were referred to as X33 and X33bis (or X33 and X33b). Here they show an unusually high level of cunning and efficiency, going to great lengths to rescue Tintin from the firing squad (in disguises that fool even Tintin) and saving Snowy from sacrifice. In this and two other early stories — "The Blue Lotus" and "The Black Island" — they spend most of their time, forced to follow official orders and faked evidence, in pursuit of Tintin himself for crimes he has not committed, the two noting in "Blue Lotus" that they never believed in Tintin's guilt even if they had to obey their orders. Except for their codenames, they remained nameless in the early adventures. It was not until "King Ottokar's Sceptre", published in 1938, that Tintin mentions their definitive names when introducing them to Professor Alembick at the airport.