Childermass knows better than to pick up random magic objects, unlike some people — cough strange cough. So the amulet gets left behind, which is just as well because SPIDER FLOOD is going to get his attention soon enough.

"Syrlya!"

He gives a start at seeing all those damn spiders and takes a step that way. He isn't wading through the spiders to get to him, though. He's stepping into the shadow of an armchair and attempting to step through that over to Syrlya's shadow. If he's successful, he's grabbing Syr and backstepping to a shadow further away from spiders.