Thanks to everyone who read my flash fiction piece "There's No Time Like the Past" and took a stab at summarizing the story. Terri Bertha came the closest to solving the mystery, so she wins a $20 gift card from MuseItUp Publishing. Below is my interpretation of the story, though all of you who commented made some very interesting theories and your ideas would probably make a better story than mine.
Despite the title and appearance of Daniel, this is not a time-traveling story. It takes place in the present day. Taylor and Scott witness some sort of UFO, and they both fall ill shortly after their experience. The air raid siren comes and goes with Daniel. Daniel is Taylor's grandfather (WWII veteran), and his ghost shows up to help lend a hand. The blinding light is a result of the UFO leaving, which forces Daniel to go as well. Realizing that Daniel was actually his grandfather, Taylor is certain he's looking out for them, giving him hope that they'll make it back home safely.