Well, the last day of school was pretty hard for me. Every time someone came up and said, "Doing okay?" I could feel the fullness of tears shimmer behind my eyes. It was a half day, and at noon I sat outside Callum's building waiting for the kids to come out. Tissues and camera in hand.

One by one his classmates emerged, a gaggle of happy geese set free for flight. Talking, laughing, hugging. Summer reflected in their eyes.

And I waited. I could see through the window as Callum sat alone in the hallway, under the coat rack. He was slowly putting things away in his backpack and sorting through the bags of detritus that every student was bringing home.

That's when I really started to feel weepy. My boy, slowly saying goodbye for the last time. I pictured us sitting in that very spot, my arm around him, sticky from the heat. How could I comfort him if I was so sad myself? Moments later, Callum burst through the door. Without a glance at me, he dashed off toward the back playground.

That's what this photo is of. Not Callum feeling bereft at this leave-taking. But Callum serious and concentrating as he seeks out the enemy in a water gun battle. Sometimes good-byes need to be just like this.