On the far side of this cavern there are four tunnels out, one of which is stairs.

It is down these stairs that Bella shortly comes racing, terrified and breathing hard and chased by a flock of toothy batlike creatures. She doesn't appear injured, but considering her preparations that doesn't mean much, especially since there's a few splotches of blood on her outfit and a few new scratches in her armor.

She spots Sherlock and runs in her direction, pursued by bat-things. "Shr-" She chokes and coughs up a blue medium-sized frog, which she catches, bewildered, as she skids to a halt before entering the water.