When gathering the materials needed to make the elyxir to save Kristin's life, Superman, moving so fast he can't be seen, takes chemicals from a science lab and some items from a grocery store. And he leaves an I.O.U. for the chemicals at the former, and some cash near the register in the latter.
During one of his most trying times during the story, Superman falls asleep and has a nice dream where his natural parents (Jor-El and Lara) and his foster parents (Jonathan and Martha Kent) get together for dinner. Pity that Saturn wakes him up by telling him he's just activated the world's nuclear weapons, all at once.