Panel a: one of 16 epochs reanalyzed with the components identified in this epoch (Nov. 14, 2010) marked. Shown is an image with the difmap modelfit components superimposed (circles) and the components belonging to the inner jet (light blue arrow) and those features that seem to belong to the spike (red arrow). The arrows indicate the dominant direction of motion. The filled ellipse in the bottom left corner gives the beam size (point spread function). Panel b: image from a later epoch. The two potential jet scenarios are indicated (see text for details). The physical nature of the spike is unclear. The spike in the two-jet scenario might be the jet of a potential second black hole. The second core (core II) is therefore marked with a question mark.