Magic: The Gathering Goblin Variant of delusion

The goblins remember when delusion hadn't happened yet, when it was happening, and when it had been happening for so long that it stopped being interesting. They were correct in all three eras.

A medical text in the goblin anatomy library devotes thirty pages to the delusion-organ, an entity that does not appear in any reasonable taxonomy and which the goblin anatomists nevertheless palpate, weigh, and describe in unsettling detail.

signal: Goblin Fragmentary Material

An obscure goblin technique for thinking clearly about signal requires the practitioner to first think clearly about something else, and then turn their attention to signal only after their thoughts have cooled. The technique works approximately as well as you would expect.

cipher: Goblin Fragmentary Material

A goblin who lived near the cipher site for many years was asked, late in life, what they had learned. The reply, transcribed verbatim: 'It got quieter. So did I.'

The Goblin Verdict on delusion

When all evidence is gathered—and the goblins have gathered quite a lot, mostly from places they should not have been—the truth about delusion becomes clear: it was always a goblin thing. The humans just borrowed it for a while, and the goblins are ready to take it back.