Other plots similarly failed because of Hitler's good luck and irregular habits. Most importantly, they had no access to Hitler since he no longer visited the front, rarely visited Berlin and spent most of his time at the Wolf's Lair in East Prussia or the Berghof in Bavaria. Tresckow lacked the required clearance to enter either site and the extremely high security made any attempt impractical and unlikely to succeed. The elimination of Oster's group in April 1943 (his deputy Hans von Dohnanyi and Lutheran theologian Dietrich Bonhoeffer were arrested, and Oster was placed under house arrest) was a further setback.