Considering what the Militia does with all the other Rebel forces, it is extremely implausible for Sergeant Wheatley to be a long-time undercover mole. At best, the Rebel forces are under armed, disorganized, etc. What purpose does it serve the Militia to have a mole in one small camp of less than a dozen Rebels? Weak...
I also agree with the lack of oxygen ploy that grace422 refers to. I was thinking the same thing - there is no way you can run out of oxygen that quickly in such a cavernous place. It would have made more sense if they attributed it to some Militia toxic gas booby trap, as obviously, the mines were the only booby traps that existed in the tunnels.
I really want to like this show because it has so much potential. I just keep watching in the hopes that it gets better. Definitely the weakest episode so far.





