Brothers of Doom

Not often we see The Shadow's incredible tolerance to pain!  This image looks like it hurts and would have had me plowing through the chapters to get to the scene that is illustrated on this cover.  If it were Batman of the 50's & 60's the answer would have been simple enough... Bat-Molten Metal Repellant.  Holy Hot Lava!
The novel is another one I haven't read yet (I'm only about 20% through the massive backlog of tales) but you can read a review of it here.