Late for an Exam

While correcting a pupil's work, I ended up writing a paragraph of my own.

I sprinted past several eggshell-coloured blocks of flats,  sidestepped past startled onlookers at the bus stop before dashing through the dull green metal gates. With my heart pounding in my chest, I plopped myself down onto my seat, next to Ben, my best friend. With a plump face and mouth agape, he started at me with incredulous awe.

"Are you crazy, Sam? Why are you so late for the exam?" he mouthed.

Before I could respond, the school bell rang.

"You may begin," the teacher said.

Oh boy.