I Play Red Alert in the Apocalypse

The zombie virus broke out and a zombie broke into my home. However, because of fear, I left my 16-year-old sister behind and left alone. I eventually died of endless guilt. But God gave me another chance. I traveled back in time three days before the virus outbreak, and also obtained the red alert system. This time, I must protect my sister and stop escaping. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.