For the time being it was within the range of acceptable risk, though. Meaning that Arthur didn't know what the hell to do about it, so why worry. This cuckoo had never stuck with any host family for long enough for the problem to become unmanageable.
Still, he heard the stories: from older members of the tribe, during their infrequent meetings, both official and informal. He'd heard that with age, you lost objectivity and distance: vital qualities for survival. You got fond and doting and foolish, you started to form bonds that interfered with your capacity to cut loose -- whenever necessary. There were some stories of tribal elders going native. It was like shape-changing, perhaps: if you waited too long to break the spell, you forgot how. You even stopped wanting to, maybe.
The word was that mortality was catching. It was a bug, junk DNA that had been quietly stealing life and years from the human tribe. So far the Fae had retained immunity, by and large -- with a quid pro quo meaning corresponding low levels of fertility.
Suspicion, or even worse, definite identification, rarely led to non-accidental mortality, though. Not executed by human kind, at least. A Fae could usually control an information crisis – too much information, held by the wrong people – and engineer a human-normal explanation that was readily accepted by most human participants in an 'incident'. (The Fae equivalent of a nuclear reactor explosion.) These humans were so irrational -- yes, even them, inventors of technology, discoverers of relativity, pioneers of the Enlightenment – proponents of fundamentalism, wagers of war, destroyers of the planet...
Arthur didn't think it so strange that they refused the evidence of their own eyes, ears and memories and minds, if it strayed too far outside the range of their everyday experience. They were so easy to confuse, so ready to doubt themselves. Sure, a man's stranger-wife appeared from nowhere overnight, his kids were calling her Mum the next day – and he only remembered this when she disappeared as suddenly as she had arrived.
* Vyacheslav Ivanov, The Silver Age of Russian Culture
