Not a bad idea

With danger imminent, his instincts once again began to do their job and provided him with a solution. The answer to his problem was straightforward. The network of tunnels he was running through was extremely complicated as is, and had an added layer of difficulty due to the fact that they were arranged in a formation of some kind. 

The purpose of the formation seemed to be specifically to confuse him. No matter how much time he took, and how he explored the tunnels, he would not be able to find an exit.

In such a situation, the answer should have been simple. All Lex needed to do was dig upwards to exit, right?

Unfortunately, even that seemed to be a trap. Vaguely, he could sense that gravity was being manipulated within this vast underground network. What he thought was down and up may actually be deceiving. There was no way to determine which direction the exit was in.