When we got home and got the groceries unloaded, Lisa decided that the loose step board on the south steps had to be fixed sooner rather than later. This is one of the boards we replaced last year, and after some investigation, Lisa determined that three of the four screws were in bad wood in the underlying beam. She left those in place (so there wouldn't be holes in the step) and drove four additional screws into areas where there is good wood on which the screws would bite. It's much more solid now and we don't have to worry about the board turning under our feet. With that done, Lisa could relax and get ready for bed.
Lisa did have a role for me to play in this repair: when she was ready to drill the new screws, she had me stand on the step so that it wouldn't wobble. Glad to be of service.