: A six-month time jump shows Langdon still at Harvard, far from Katherine in D.C.. Because the 10-episode season exhausted the plot of the novel, the series ended there. The Ending The Lost Symbol Season 1 Explained - Looper
: Peter Solomon arrives, intending to sacrifice himself to save Katherine. However, Mal'akh reveals he wants to be the one sacrificed by his father's hand to be reborn in a higher form.
: Mal'akh takes Katherine to the tunnels beneath the Washington Monument , planning to use the "Cascade" resonance device to achieve apotheosis (becoming a god) through a ritualistic human sacrifice.