Zepkow is a small municipality in Germany.
Wolfgang von Strucker's Vaults
Wolfgang von Strucker, a high-ranking member of the terrorist group HYDRA, had establish a large number of vaults in various locations. These contained numerous supplies and artifacts that von Strucker and HYDRA might need to aid them in their plans. Von Strucker's vault in Zepkow was among the most important of these, as it housed a fragment of the Monolith that was used by ancient Inhumans to banish the HYDRA Society's ancient leader.
After HYDRA suffered a series of crushing blows, the new head of HYDRA, Grant Ward, began looking for Strucker's secret vault. After a brief power struggle with Gideon Malick for leadership of HYDRA, the two agreed to work together. Malick was impressed by Ward's ability to escape the death squad Malick had left for him and track his location; Ward agreed not to kill Malick in exchange for information pertaining to HYDRA's origin. Malick revealed the story of Hive and how HYDRA had been trying to bring the rogue Inhuman back from the other world for centuries. He agreed to help Ward destroy the second incarnation of S.H.I.E.L.D. if Ward would give up information on how Jemma Simmons' return from the same planet was orchestrated.