Perform Rituals. Troops of kalkes inhabit trees, caverns, and ruins around sites of significant magical activity. Twice a month, or more during major astrological and seasonal events, the kalkes gather to perform-by way of dance, chant, and sacrifice-an imagined rite of great magic. The effort has an equal chance of achieving nothing whatsoever, causing dangerous but short-lived misfortunes (snakes raining on the countryside, creatures summoned from the lower planes), or triggering calamities (great fires or floods).