Getting in Trouble

I did not mean to get in trouble, I really did not.  I am heartily sorry for my failure to be prompt and quick, but I still do not know exactly what happened.  

 I was supposed to fetch the second kid from school and bring him to the dentist.  Master was already at the dentist with the first kid.   I left there with what seemed like plenty of time, and didn't get back for 45 minutes. We were really, really late for the appointment.
  Master said the school is only 5 minutes from the dentist.  And I may have waited 5-10 minutes for school to get out rather than interrupt and get him out of class, because I thought it would not make a difference.   Somehow it took so long that both the dentist and Master became worried about me, and since she was harassing him every few minutes with "Where are they?  I thought they'd be here by now?" by the time I got back Master was furious.   First he quietly berated me in the office, then he said he'd drop it for now but there would be my ass to pay later.  
Ugh.   I was miserable.  I don't know where the time went and I swore I had taken no detours or side trips.  There was some traffic, but no parades or anything holding me up.

Last night he was too tired to do anything to me, but he's most likely going to punish me tonight.