Samuel emerged from the ground like a ghost right in the middle of a massive construction site which looked abandoned at the moment.
It was barely a mile away from where he took Clark from, so basically he had him right under their noses.
The reason why he was confident that no one could find him was because he practically used all his magic to dig a tunnel straight through the ground and made a small chamber to put him.
To reinforce the structure he melted some already available steel making sure the place wouldn't collapse. Even the entrance was hidden by him placing a huge slab of concrete so that no one could even guess there was something beneath it after all, it weighed tons and no one would be dumb enough to use sich a large slab of artificial stone to block a tiny hole.
