Following hanging up, you might face the final battle in this mission. Head to the next floor to gather some ammunition — they will turn out to be useful while in the upcoming battle. Be attentive and cautious, as zombies will surface endlessly right until you defeat the leading mutant. https://lorenzotngxp.blogkoo.com/the-greatest-guide-to-call-of-duty-black-ops-6-gameplay-walkthrough-campaign-53387648