"I've climbed trees." This was probably more like tree climbing than rock climbing, which Ian hadn't tried. With the blob chasing them it was academic - he was sure he would find a way to get up there and away from it.

"I'll go first. You shoot it if it gets too close." So far they'd only seen the blob move along the ground, but that didn't mean it couldn't float upwards if it needed to. It had already made it to the top of the tunnel, so there was no time to waste.

Ian stepped onto the first knob and hauled himself up. They were further spaced apart than a ladder, but at least they didn't have branches in inconvenient places. He was a couple of feet up when the knobs started getting slimy. "Ugh." There's some sort of slime up here. Not that they were in a position to stop, but the slime gradually got worse and he was having to wipe it off the visor with his arm - which was also slimy so it just made the whole thing a blurred mess.