The night my heart stopped beating

Last night was not a good night. I had the scare of my life. It was 2am when I woke up due to Isabel's door being opened. She usually does not get up in the night, but when she does it is because she has to use the bathroom or she has had a bad dream. I waited for her to come into my room, but she never came. I must have woken up Ryan with my moving, so he got up to see where she went. He then came back looking disoriented. I jumped out of bed, for some strange reason, feeling like something was going on. I said, "where is she?" He said, "I don't know". So I ran out of my room starting to look for her. I looked in her room, not there. I looked throughout the house, not there. The I heard this blood shrieking scream. I turned to Ryan and said, "it came from outside". I flipped on the outside light and ran outside. I heard another scream and then I yelled, "Isabel". I ran out toward the garden and I could hear her yelling, "mommy". It was so dark it was hard to see her, then I saw the white parts of her jammies in the dark. She started running toward me, tripped on something in the yard, and then ran into my arms. I started getting tears in my eyes, I was so overcome with emotions. When I initially heard her scream, I was so afraid she was being kidnapped or some wild animal was hurting her. It was the scariest scream I have ever heard! We went inside and I kept asking her why she was outside, she just kept saying, "because I was outside". We put her back in bed, but I was now wide awake due to the large amounts of adrenaline running through my body, plus running to find her had giving me leg cramps in both legs. I was in no condition to fall back asleep. I sat in bed rubbing my legs, trying to relax. About 10 minutes later I heard Isabel scream. I went into her room and she was sitting up. She said she could not fall asleep, so I laid down next to her. While I was laying there she said, "Why was daddy in the garden?" I said, "He wasn't, I think you dreamed it." She said, "No, he was calling me to help him in the garden." Well, that explains why she ended up out by the garden at 2 in the morning. She must have had a dream about helping Ryan in the garden, walked out there in her sleep, and then was woken up by the cold air or something and screamed because she was disoriented and confused. It was the scariest thing ever! I have never been more afraid of losing her. I think it's a parent's worst nightmare, not being able to find your child and then hearing a piercing scream. I hate to do it, but I think I am going to put a doorknob lock on her door for the next couple of nights.