Darkness

"Is it working?" Gard asked quietly.
"Yeah," I said, my eyes still closed, focused on the illusion. I fumbled about until I found Mouse's broad back, and rested one hand on his fur. "Stop distracting me. Walk."
"Very well." She drew in a short breath, said something, and then there was a snapping sound and a flash of light. "The rune is active," she said. She put her hand on my shoulder. The malks weren't using any light sources, and if a group of apparent-malks tried to walk through with one, it would kind of spoil the effect we were trying to achieve. So we'd have to make the walk in the dark. "We have perhaps five minutes."
I grunted, touched my dog, and we all started walking, trusting Mouse to guide our steps. Even though it was dark, I didn't dare open my eyes. Any distraction from the image in my head would cause it to disintegrate like toilet paper in a hurricane. So I walked, concentrating, and hoped like hell it worked.
I couldn't spare any brain-time for counting, but we walked for what felt like half an hour, and I was getting set to ask Gard if we were through yet when an inhuman voice not a foot from my left ear said, in plain English, "More of these new claws arrive every day. We are hungry. We should shred the ape and have done."

Side Jobs Heorot, Page 132-133