The first time I read "The Gardener" I thought that when the "gardener" tells Helen "Come with me, and I will show you where your son lies," he was acknowledging that Helen had loved Michael as though he were her own child. That she had suffered a loss as great as a biological mother, in the same situation, would have suffered. After all, if Helen were actually Michael's mother, then she's done something quite terrible, especially within her own social context: she has blackened the name of her late brother, has falsely portrayed him as the father of an illegitimate child, in order to cover her own sin. And that's scarcely admirable.
Buf if that were the case, if Helen had been telling the truth about who Michael really was — if Michael had "merely" been her nephew — then much of the story becomes pointless. Why then do we hear from the Lancashire woman whose son enlisted in the army under a false name? Why do we hear Mrs Scarsworth's agonized confession that her primary reason for visiting the graves is not to carry out her "commissions" but rather to visit the grave of her lover, the man who "ought to have been nothing" to her but instead was everything? (And then there's the strangeness of Mrs Scarsworth's last words to Helen, which suggest that she somehow knows that Helen is hiding something. "It.") Kipling shows in these scenes a series of lies about identity, a series of secrets. Why?
But those questions are answered if Helen is Michael's mother, and if her own history is one of secrets and lies. Look back at the beginning of the story: "Every one in the village knew that Helen Turrell did her duty by all her world, and by none more honourably than by her only brother's unfortunate child." This could be a statement of mere fact — or it could be like the opening sentence of Pride and Prejudice: "It is a truth universally acknowledged...." In many villages, what "every one knows" is not in fact true at all.
Perhaps what sent Helen to the south of France was not lung trouble after all. Perhaps, since her brother was already known as a ne'er-do-well, a slight darkening of a dead man's already-bad reputation was a small thing in comparison to the social ostracism that Helen would have experienced had she acknowledged herself as an unwed mother. Moreover, by frankly admitting her brother's sin, Helen could demonstrate to the whole village that she "was as open as the day," and genuinely "held that scandals are only increased by hushing them up." Thus also her risking young Michael's rage by telling friends that in private he called her "Mummy" — a rather painful bit of truth-telling that could only have solidified the village's belief that she "was as open as the day." Mrs Scarsworth had only to remain silent; Helen had to construct, painstakingly, a complex edifice of lies.
And so we return to the "gardener," who knows all this, who knows Helen's every deception — but who also knows the great weight of the burden she has laid on herself, a burden now impossible for her to shrug off. The world cannot know that she has lost a son, and this only adds to her already immense grief. And so He looks into her eyes with "infinite compassion," and says the words that tell her, simply, that he knows her great secret, that he does not judge her, and that he mourns with her as she mourns.