While 'babysitting' the new shinigami girl, she sneak away from Ichigo and went to a graveyard. There she a big guy appeared and grabbed her by the throat. Fortunately, Ichigo came and cut that big guy's arm off.
With the big guy, there were others with him.
Rukia came back from the Soul Society but she didn't came alone. She came with a few captains and vice captains with her to detain the new shinigami girl.
Why would they want to detain her? The answer is in the video clip Part 2 of The Bleach Movie - Memories Of Nobody above (be patient waiting for it to buffer).
