This is another dado close to the end of the bookcase side piece. As "luck" would have it, on the
last cut the little section of wood on the right side "blew out" on one of the panels because the
plywood laminations had gaps and were weak. So tomorrow I'll have to glue in a "patch" and try again.

I'll post photos of the "fix". It'll be hidden and never seen otherwise, but I want the joint correct.