Finding the Plot

I've been slowly gathering bits and pieces - characters, situations, images, emotional registers, background data - for a new novel, and now I'm trying to piece things together, and give the various strands trajectories, velocities, and a common destination. As usual, I have several strong pictures of various events along the way, but don't have much idea of what binds them together. That'll come later, out of the behaviour of the characters and their reactions to the situations and problems they find themselves in.

Hopefully, anyhow. I always find this a messy, murky process, and I have no doubt that I'll end up groping my way down several dead ends that have to be thrown away and recycled before I see a clear way through from beginning to end. I do have a rough shape of the novel, though. It looks a bit like this (Alika and Japer are the two protagonists; the child, the Clade, the Ghosts and the mystery guest (?) are Powers):