Mum is too sure, but if there are only three people in the house
it could be either John, Abel or Grandma.
If your story is correct, just wait for Abel or Grandma to return
and verify.
In reality, there is only John and Mum in the family.
John says "But Abel did it!".
Mum goes "John, don't scare me..." *sobs* "you are my only son...
who is Abel???"
