Today, Wizards of the Coast released the contents of the Signature Spellbook: Jace special set. This set features 8 cards based around Jace Beleren and includes a random foil of one of the cards. There are some good ones in the mix including Gifts Ungiven, Mystical Tutor, and Threads of Disloyalty.
The set will be available June 15, 2018 with a MSRP of $20.

 

Jace Spellbook cards

 

Official details can be found here.