Twist transfer and propagation after the reconnection. (a)–(d): Evolution of magnetic field lines near the outer spine. The arrows point to the curvatures of the traced field lines. The ellipses in panel g indicate the plane to calculate the averaged mass flux in Fig. C.2. (e)–(g): Evolution of the representative field line around the outer spine (blue) and the representative flux rope field line (yellow). (h)–(j): Evolution of the distribution of the twist number measured in turns in y − z plane outlined in panel a.