(Strip Number 621, Original Publication Date, 1 June 1984)
Panel 1: Later that day, we find John looking out the window and telling Mike that Elly has taken Lizzie to the hospital. Mike asks "How come?"
Panel 2: John tells him that her fever is worse and they were getting worried.
Panel 3: He tells Michael that Elizabeth will be fine and to go back to bed.
Panel 4: Michael responds by saying "Promise?" and looking really freaked out.
Summary: I can understand his being anxious; after all, he put a lot of work into raising Lizzie on his own and wants to make sure that it isn't going to go to waste.