Yippee. I'd rather have been wrong about today.
Panel 1: We're on the bus to whatever Mike attends and Lawrence tells him he missed Pizza Day, Painting Day and a movie. Mike's response: an anachronistic "Bummer".
Panel 2: As Lawrence starts to explain that a fireman is coming, perhaps to remind them that in an emergency rushing back into burning buildings is a stupid idea, Mike notices that Deanna should have gotten on now and wonders why she hasn't.
Panel 3: Lawrence says she's gone and moved away. They had a good-bye party with cake and everything. Everybody was there.
Panel 4: Mike thought-bubbles that his body wasn't.
Summary: Don't worry, Mike; she'll come back into your life like a broadside accident. Then you can marry her and have children to flee from.