I will only mention this one more time…  And, yes, I know exactly what I am doing here… if the cave mouth has collapsed, then from whence is the light emanating- the light that causes Mark to appear in silhouette?

Toast, Ladies and Gentlemen, Toast.  That’s what they are, unless of course there’s a back door to this thing?  Perhaps they did already have some gear in the cave?  We can only hope…  The bats will probably lead the way- if their main point of access and egress is blocked, then nature will have them find another one… in the words of Ian Malcolm,  “Life, uh…Finds a way.”