Pre-flare and post-flare activity in AR 10930 on 2006 December 13: (a) pre-flare state of the corona; (b) SOT magnetogram with yellow box highlighting the energy-production region; location of the magnetogram fragment is shown by dashed box in panel (a); (c) well-developed process of energy release in the chromosphere; (d) well-developed multi-thread system at 10 ⁴ K temperatures; (e) self-organized arcade in the corona lasting from about UT 02:45 to UT 08:02. Green arrows mark the surviving long-living loop systems.