My Last Time Babysitting horror story

I checked my watch as I walked up to the door. 10 minutes late. I had been babysitting for them for six months. I was sure they wouldn't mind. Mr. Lopez answered the door. 'Hey, I'm sorry I'm late,' I started to say, but stopped when I saw him. His face was soaked with sweat, and he looked slightly agitated. 'No problem at all, come inside.' In the kitchen, there was only a single light on above the table. At it, Mrs. Lopez was writing something feverishly on a slip of paper. 'I'll be right back. I have to say goodbye to Denise.' Denise was their 1-year-old daughter, who I had been watching for them. She disappeared into the darkness of the hallway, heading up the stairs. 'What movie are you seeing tonight?' I asked, setting my bag down on the table. 'Oh, I don't know. I guess we'll decide when we get there.' Mr. Lopez was shifting from foot to foot, looking more worried by the minute. I noticed a cut on his right cheek, dribbled with dried blood. 'Are you okay, Mr. Lopez?' I asked, but before he could answer, I heard Mrs. Lopez returning from upstairs. 'We... we should get going. Goodbye, Katie,' she said, pulling me into a hug. She tightened her grip for a moment, and I could have sworn I heard a soft sob. 'Thank you for everything,' she said with great difficulty. She began to say something else, but her husband grabbed her and dragged her out the door. Before he closed it, he gave me a mournful, almost apologetic look. Then he closed it, and I was alone in the dark house. I thought about going out and talking to them more, or maybe even just leaving, but in the end, I decided to stay. Not turning on the lights so as to not startle Denise, I climbed the stairs in the dark and headed into her room. I approached the crib and was about to lift her up when I saw a note lying on top of the blanket. I read it by the streetlight that glared through the window: 'Katie, I'm so sorry. He broke in while we were getting ready. He said he was going to kill us, do horrible things to Denise. He asked if we were expecting anyone, and we told him about you. It's an exchange. I'm so sorry. I hope that God will forgive me one day.' Looking out the window, I saw them pulling out of the driveway. Mrs. Lopez was holding Denise. She was crying while she waved at me sadly. Yeah, huh.