Hi! On year 2,polyjuice potion. At the start of the level and tryin to find the ingredients for the polyjuice potion. There's a spider spitting fire at me though and I can't get past the fence to get to the other side where I can see mushrooms and stuff. I tried stunning it and it works for a few minutes coz it's lyin on it's back but then it gets up again,I've tried stunning it again and just shooting at it with my wand before he gets up but nothing helps. Please help,I've been stuck on it for ages and it's really annoyin me! Thanks.