When Claire goes to visit Margaret Campbell, Margaret has a “vision” and tells Claire:
“Gleep, gleep. Gleep, gleep. D’ye hear ’em? D’ye hear the tree toads lullaby? And the moon — the moon be chokin’ wi’ blood. Ye must be careful, Abandawe will devour ye. Abandawe, Abandawe. Abandawe…”
This ends up referring to the standing stones in Jamaica. Margaret is warning Claire about the passage through the stones. One can assume the “chokin’ wi’ blood” could refer to Geillis’s death.