Story - Shadows over Innistrad

I've been playing for a month or so, spent some money, QB, events, all that. Yay, fun. When I'm not in the mood for QB I'll go into Story mode and grind for crystals, but I can't access Shadows over Innistrad. I've Googled, searched this forum, searched sub-Reddit, and find nothing about it. Yesterday I cleared Battle for Zendikar with Sorin just to see if it would magically unlock SOI, but no luck. I've played the tutorial, but the Chapters are not there. Heroic Encounters are available, though I've not cleared them.

What the heck is the deal?