Reorder Posts

I have a category with a few posts under it kind of like a series, but I would like to be able to order these posts not by date.

I had a look for a plugin that would do drag and drop reordering or something like that, but can’t seem to find one anywhere. Does anyone know of a plugin or another way to do this?

I could use a custom field, but if I had 10 posts and I wanted to put a new post just under the first one, I would have to go through 9 other posts changing the number in the custom field to get it right.