Pursuit of the Sun 1.2

Unfortunately, Ottar somehow didn't know anyone in his own cult. But he could do something himself...

– Hmm, there's no one suitable. But... I can brew invisibility potions. My condition isn't great right now, but if I give such a vial to someone clever and agile, it won't be difficult for them to keep an eye on the witch's house. I doubt this creature has heightened hearing or vision," Ottar smoothed his beard, which had been in need of a trim for a long time.

And from invisibility, one could set up an ambush... True, invisibility is a rather grand name for the effect of Ottar's potion.