The Beinz Blood Lake was a sacred ground for the Disciples of Glory. All along the lake, there were outposts set up by the Church's knights. Any adventurer or mercenary group who had gotten the Church's approval to venture into the area would need to report themselves there before being permitted to operate within the approved parameters. Even though there were many incidents near the lake of late, which resulted in the management of the place being a little messy, this basic rule was pretty much ironclad.
While the Blood Lake was indeed sacred grounds, it was not forbidden grounds. The checks made for approved mercenaries were pretty lax and Hilda managed to get through by identifying herself as part of Hao Ren's party. The group then went towards the rest area on the elevated platform by the lake.
