I have no idea what Solvunn did with them. They whisked them away somewhere secret almost as soon as we got back...

[She tries to think back. It was a year ago now, but information is sort of a niche for her.]

I do know that the original intention seemed to be Thorne wanted to feed the Singularity during the Dimming, but the other two factions are wary of it having too much power. I never really understood what they assume will happen if it's overloaded, but I know Winifred Bordeaux in Solvunn was particularly concerned about that, and of Marlo Reiner getting her hands on raw energy like that.