Taking the title from Brandon Sanderson's book series The Stormlight Archive, where a soulcaster is an instrument that transforms one object or life form into another; Joanna Mattrey transforms her viola and a tromba marina, aka a nuns' fiddle, with preparations, objects and unusual approaches through technique, creating a remarkable set of 11 unique and inventive improvisations.

Performing on viola, violin and a stroh (a string instrument mechanically amplified by a metal resonator and horn attached to its body) the NY duo of Joanna Mattrey and Gabby Fluke-Mogul present eight dialogs of ominous and prophetic divination, titles including "The Vision", "The Potion" or "The Omen", as they weave and tear at their strings in startling and impressive ways.

The first solo record for NY violist Joanna Mattrey, performing also on the Stroh violin, in a deep exploration of the sound possibilities for both instruments, using preparations to alter the resonance of the viola, masking its overtly singing and beautiful nature and allowing for unexpected and unusual textures which weave around melodic lines; unique and fascinating.