I am planning the next campaign while the current one comes to a close. Our group favours sandbox play and I facilitate that with [Icar's](http://www.icar.co.uk) event driven system. While writing down the list of events needed to fill the campaign with interesting plot hooks and set pieces, I was wondering if it is wise to plan a big finale.

I want to avoid fizzling out and at the same time I don't want to railroad the players - they won't like it. Should I have an inkling of the end before we start?