Near midnight she pedals her rented bike past Checkpoint Charlie. Vacant, but suitably restored, the off-white, utilitarian guard box occupies the middle of the street, protected from a barrage of selfie shots by window-high sandbags. She rides on, under streetlights' glow, swerving to avoid a lone tourist bus pulling its towering frame away from the curb, the last remaining block of a roadside barricade spontaneously assembled and disassembled each day. Ahead, in the unnatural blue of the bike's LED headlamp, she spies an unbroken pathway built into the roadside, two cobblestones wide, disapp