Skeletons attack the players.
There should be two skeletons per a player. Half the Skeletons will have spears, the others scimitars.
The players stumbled onto their burial site.
The players may fight the skeletons or pray they find their peace, in which case they will go back to their grave.
If the players killed the skeletons, Captain Red Beard O’Neil will hunt them down, having seen the whole thing in his dreams.