These were of no interest to Gelert.

The final disillusionment came when Sirius began to realize that Gelert not merely would not but could not talk. This suspicion had long haunted Sirius, but he had believed that Gelert's unresponsiveness was merely due to his haughty disposition. There came a day, however, when this theory ceased to be possible. Young Sirius, whose four-foot locomotion was far more developed than Plaxy's running, had been trying to keep up with Gelert at the outset of a hunting expedition. They came upon a sheep with a broken leg. Though Gelert was not in the sheep-tending profession, he knew very well that sheep were things to be cherished. He knew also that Mr. Pugh of Caer Blai was in this ease the responsible man. He therefore hurried off to Caer Blai, far outstripping the loose-limbed puppy. When at last Sirius arrived in the farmyard, he found Gelert making an inarticulate fuss around Pugh, vainly trying to persuade him to come up the hill. Sirius knew that he himself could not make Pugh understand, but he knew also that he could explain to any member of his own family. He therefore set off to find one of them and encountered Giles on his way home from school. He pantingly told Giles the story, and the two hurried to Caer Blai. Giles momentarily forgot the great family taboo about "not telling people about Sirius," and said to Pugh, "Sirius says there's a sheep with a broken leg in Nant Twll-y-cwm, and it may get drowned." Pugh looked at him with incredulity, but was impressed by the boy's earnestness and the antics of the dogs. He accompanied them up the valley, and there was the sheep. After this incident Sirius regarded Gelert as a nit-wit, and the farmer suspected Sirius of being an altogether "super" super-sheep-dog.

The discovery that Gelert could not speak, and was in other respects also a half-wit, was a shock to Sirius. Gelert excelled him in all those ways in which he outshone his human friends, in speed, in endurance, in scent and in hearing. For some time he had taken Gelert as his model. Mimicking Gelert's taciturnity, he had even tried not to talk. So successful had he been that Elizabeth in one of her letters to Thomas said that Sirius's human mentality seemed to be waning. The realization that the older dog simply could not talk changed the puppy's attitude. Suddenly he became garrulous, and showed an increased desire to keep pace with Plaxy in acquiring all sorts of human skills. Also he devised an amusing way of ridiculing Gelert. He would hold imaginary conversations with the supersheep-dog, pretending that Gelert's silence was due to deliberate taciturnity. The older animal would at first ignore the garrulous puppy; but presently, particularly if the spectators laughed, his super-canine though sub-human mind would begin to suspect that Sirius was making a fool of him. He would look very self-conscious and perplexed, and sooner or later drive the insolent youngster away, or seize him and chastise him.

Plaxy was by now being taught to read and write. Her mother devoted an hour a day to this task. Sirius had at first shown a mild curiosity about the queer business, but under the influence of Gelert he had thrown it over for the sake of hunting. Elizabeth made no effort to compel him to carry on his studies. Either his distaste was a passing phase, soon to be outgrown, or his mind was after all not sufficiently super-canine to persist in this alien occupation, in which case compulsion would be disastrous.