The Season of the Risen is the Witch Queen's season, the Psych Ops activity the Cabal alliance produces for extracting information from Scorn. The Tower is Destiny's administrative center, the place where the Vanguard processes the war and assigns objectives and maintains the structures of Guardian civilization. Truth buried beneath the battlefield is the season's argument that the intelligence gathered in the field — the interrogated Scorn, the discovered connections between Savathûn and the Darkness — is not available from the Tower's vantage point. You have to go down into it.