CAD-FAC architectural plans
The CAD-FAC architectural plans symbolize Donald's uncertainty. When Senator Thurman approaches Donald and asks him to construct the silos based on his architectural plans, he gets confused. Donald needs to learn the intended purpose of the establishment. Donald also does not understand why Anna, Thurman's daughter, and his ex-girlfriend kept the plan away from him for several years. After Donald accepts to undertake the project of constructing the silos, his life becomes more complicated than ever. For instance, Donald loses everything, including his family and his mind.
Propranolol
Propranolol is a simple drug that symbolizes human manipulation. The workers of the silos are compelled to take Propranolol to lose their memory and concentrate on working in shifts in the silos. Donald becomes a victim of this drug while working in silo 1. After taking the drug, Donald loses his memory and falls into depression. The same happens to other workers in the silos, including Troy. After the shifts, the workers return to sleep for decades before they are woken up to continue their shifts.
The bomb explosion
The bomb explosion symbolizes Anna's denial to move with her life after breaking up with Donald. Anna orchestrates the explosion intentionally to separate Donald from his wife, Helen. Ann is determined to use all dirty tricks to get closer to Donald, and she achieves this goal when Helen is killed in silo 18.
