Whilst temporarily without their hyperspace drive, which has apparently broken down, they land on a planet with Earth-like gravity and atmosphere, and find an advanced agricultural civilization, with grain-like plants tended by short four-legged beings.
The beings show the two visitors hyperspacial sighters (valuable instruments for galactic navigation), despite the planet never having been visited by humans before.
They indicate that more of the instruments are to be found on the neighbouring planet and the explorers leave in a hurry to visit it, never stopping to consider the impossibility of the situation.
Back in the spaceship, Chouns, who is known for his 'hunches', eventually realizes what's happened; that they've been telepathically 'conditioned' to transfer pollen from the plants (who are the real masters) on one planet to the other.
Chouns believes that he must immediately warn Earth of this threat, as he also realizes that one of the two animal species must have at one time been capable of interplanetary travel.