Seeking to figure out how to solve this puzzle, we tried to contact the Fire Witch whom we have helped in the past. She revealed that she, too, was investigating the case, and mocked our customer for withholding vital information from us. It turns out that half of the solution is waiting for a 'Zombie Guardian' to come out of the portal and capturing such an individual, who is sentient enough to be interrogated. The other half is blowing up a portal before it disappears and analyzing its remains. The Fire Witch had already done both, many times, but she couldn't figure out the portal by herself, so {ALT}she passed the remains to us.{ALT} She was however unwilling to share any Zombie Guardians, claiming that she is still researching them.