NBC cancelled The Enemy Within at the end of season 1.
It is doubtful that any other venue will pick up extending it beyond the original 13 episodes. It never seemed to attract much of a viewership.
I watched it, also. The final episode did sort of have closure and the BIG cliff-hanger.
I just watched the Pilot Episode of “The Enemy Within” and thought it was a real stinker. It’s such typical TV fare with everything moving about a thousand times faster than real life, totally implausible plot lines, and constant ominous music.