From the preview:
Paladin Vasen Cale is doomed to straddle the worlds of light and shadow. While Loyal to the god of the sun, Amaunator, Vasen cannot deny his heritage as the son of Erevis Cale, shade assassin and Chosen of Mask, the god of shadows. The day has come when Vasen must assume his role in the Sundering. He knows not what that role will be, only what his father tells him in dreams: do not fail.