I had something come up in Chef's Request and wanted to see everyone's thoughts. So, I've attached a map of the situation. Brown Dragon is up and wants to shift to J4 to get a shot of the squishy Psion, Calisto. Ghorgor, the goliath battlemind, doesn't want that. The dragon attempts to shift to J4, but Ghorgor uses Blurred Step as an Opportunity Action (therefore an interrupt) to shift to J4 hoping to block the move. Now, I was thinking that because the shift for dragon wasn't valid anymore, the dragon still had his move action left, so he would shift to J5 to get at Calisto still. One of the players believes that the interrupt stops the movement and therefore the dragon's forced to attack Ghorgor.