Our school trip

6 formers go on a school trip to a castle 2 hours away from there school , but it wasn't long before disaster strikes . They get split up into 4 groups but 1 group is finding it harder than the other 3 . 1 group goes into a dungeon to collect missing peaces for the puzzle and a girl accidentally walks into a invisible portal what leads her into a other dimension , so the whole class apart from the teacher( mr Smith) has to find away to bring her back before the teacher find out . Will she get out or will she get trapped in there forever ...