Spots' Adventures

On the last day of school, Spots finds a mysterious letter in his locker that has a bunch of symbols. For the rest of the day, he feels like he is being followed by someone. Every time he turns around to see who it is, he sees a solid streak of black zoom away from his sights. He goes to the library to search up codes to see if any of them match with his note. When he finds a code cipher that matches with his, he figures out that the code says "Ilqg wkh hoxvlyh zhlwh vkdgrz" which makes no sense at all. He finds an old friend at the library that helps him find the cipher to the new code and they go on an adventure to find the elusive white shadow.