It’s Halloween, so let’s talk about something scary: crossing the Chicago River on a tight rope 50 stories up. That’s exactly what Nik Wallenda will attempt this Sunday. He’ll be crossing from the Marina City west tower to the roof of the Leo Burnett building. There’s still a few details up in the air, like whether Wallenda will be forced by the state to wear a tether or use a net, but however things go down (and here’s hoping they don’t go crashing down), we’re scared at just the thought of it.