Abraham Lincoln: Vampire Hunter star Benjamin Walker will play the title role in the drama, which follows a US missionary who becomes caught up in a Cold War crisis in East Berlin.
Plemons - who recently appeared on AMC's Breaking Bad - will play a character named Sherwood Elbridge, Deadline reports.
Elbridge is a young Coca-Cola executive who secretly smuggles defectors out of the Eastern Bloc.
24-year-old Plemons is best known for his TV roles and for appearing in such films as 2011's Paul and this year's The Master.
His Breaking Bad co-star Aaron Paul was originally linked to the lead role in The Missionary pilot, which ultimately went to Walker.
The Missionary has been penned by Love and Other Drugs writer Charles Randolph, who will exec produce alongside Hollywood star Mark Wahlberg.
Baltasar Kormakur (The Deep, Contraband) is attached to direct the pilot.
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