Yithian.
Action: Pay X (which must include at least one [Yog-Sothoth] resource) to choose a non-Ancient One character of X skill or less. The controller of that character gains control of Professor Nathaniel Peaslee and you gain control of that character.
"It was on Thursday, 14 May 1908, that the queer amnesia came... I had a singular feeling - altogether new to me - that some one else was trying to get possession of my thoughts."