It will be released on April 8, 2016.
The official expansion code is SOI.
Mechanics and Keywords
- Delirium (Active while you have four or more card types in your graveyard.)
- Investigate (As well as Clue artifact tokens.)
- Skulk (A creature with skulk can't be blocked by a creature that has more power than it.)
The promo cards for the five intro packs are: