Timothy silently enters their house in the forest of Naupaka Mountain. The lights were off and only the lights in the wall lamp outside the house were on. He assumed that his parents were already asleep so he made his way to the stairs as quietly as possible so as not to wake them up.
But on his way to the stairs, he noticed the sliding glass door that leads to the back porch is slightly open. He was not worried that someone would sneak inside their house because they were in a secluded and private part of the mountain. He has been living there for years and not once did they encounter people getting lost in that area. It was one of the reasons why his father bought that place to build his mother's dream house.
So, Timothy guessed that his parents probably forgot to close it after they hang out, which they always do after dinner before going to bed.
