Stowaway to the Mushroom Planet

An invitation the boys send to a university professor reaches his assistant instead, and Horatio Peabody works out that a world nobody has catalogued is the making of a career. Tyco Bass's cousin Theo, a world traveller coming back to his ancestral home, has rebuilt the lost ship. Peabody gets aboard it without being asked, which is how the second Mushroom Planet book acquires its stowaway.

The book is an argument and Cameron does not hide it. Peabody's position is that Basidium must be explored and exploited for the good of science, with his own name attached; the boys' position, learned from Tyco Bass, is that the place is somebody's home. Peabody settles the question himself by committing an act of sacrilege on the planet that comes close to getting all of them killed. What he takes home is not a discovery but a limit — that the certainty of his own scientific authority was the dangerous thing in the room.

It lands for a child who has already read the first one and wants to go back, and it is the more topical of the two: it is about what visitors do to the places they visit. The reservation is that the wonder has been spent. The first book gives its pages to finding something; this one gives them to an adult who exists in order to be wrong, and the lesson arrives on schedule. Read them in order, or the argument has nothing to push against.