Top panel: photospheric field just before the beginning of the C1.0 class flare as observed by SDO/HMI. The red/yellow arrows represent the transverse components of the magnetic field starting from negative/positive B_z values. The orange line is the PIL. Bottom panel: spine-like structure and its surrounding current envelope. The current density is represented by the brownish semi-transparent isosurface (at 26% of its peak volume).