It was a young adult science fiction story, which I read in grade school, meaning late '70s, early 80s. It took place in the near future, when air and water were becoming polluted beyond redemption, and food and electricity were rationed. The protagonist is a teenage boy who lives with his dad, the mother having disappeared some time previously. The boy keeps a hidden farm where he grows vegetables using stolen water and power. He is trying to find his mom, who, it turns out, has joined a group of people who have gone into suspended animation to await the eventual death of humanity and are planning to re-emerge when the planet has become clean again. These people are in underground bunkers the key to which is to pour mercury into a lock shaped like and infinity symbol. I think the title is “The ______ Club” but I could be wrong. Anyone remember this?
Crash. I mean, bump. Anyone?
You garbled a few details I think (it’s been many years), but I believe you’re talking about The Missing Persons League.
Ding! Yes, that is it. Thank you so very much.