Please respond quickly! I'm somewhat new to hermit crabs. My friend had some before and I absolutely adore them

I have two purple pinchers, Potato and Hobostein (Pronounced Hoboshtein) Hobostein decided to jump out of his shell while I was cleaning their tank and started digging around. Potato tried to go after him so I separated them. Hobostein then proceeded to molt on the surface after trying on a new shell or two. His exoskeleton is still in the tank and last night he was in a shell with his legs sticking out. I saw his leg move so I knew it was him and not the skin. This morning I went to check to see if he ate and I saw two of his favorite shells were moved. I looked inside every shell but didn't find him! There aren't any signs of tunnels or holes anywhere in the tank

please help! Is he just really deep in the shell? I really don't want to hurt him if he's buried and I don't know it.
My tank has a hood with a latch. They've both climbed up but could not get out.