Ok, so here is one of Atlach-Nacha's abilities while he stirs - "all Mystic cards are discarded without their special effects taking place." So does this mean the card is discarded as if it never happened (therefore no new gate and clue token are placed) or are the "special effects" mentioned ONLY referring to the written text (and therefore a gate and a clue token are placed as usual)?

(I apologize if this has been answered before, I did look and have been unable to locate same)

Only the special effects (as with Ithaqua and Weather cards, and with Tsathoggua and Urban cards). Do the gate, clue and monster movement as normal.

Cthugha, from Innsmouth, does discard Weather cards entirely, just to be different...