Publisher's blurb:
In the world of Crystal Heart, people's hearts are literally made of stone. Agents of the mysterious organization Syn scour the world in search of Crystals, powerful relics of a bygone age.
Syn Agents replace their hearts with these Crystals, which grant incredible powers... but also affect the bearer’s personality in unpredictable ways.
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[The] Player's Guide...includes only the first few chapters of the book (those that don't have any secret stuff), to share with the group.