The Old Task Force didn't directly head to Wasteland Ruin 13 to investigate the Holm Fertility Center because they still had some preparations to do.
On the one hand, their planned route was to enter from the cave which the white wolf used in the North Shore Mountains. After all, their destination was closely guarded by First City's army, leaving only a single gap. However, the Old Task Force had previously exposed their identity as Ruin Hunters, and First City had a mission to investigate the missions they had previously participated in.
Jiang Baimian wasn't sure if this large faction—which had plenty of powerhouses—had grasped this secret passage and placed it under surveillance.