Kat is thrilled to be competing in her first junior tennis championship at Melbourne Park. But things are off to a horrible start. Her doubles partner, Miri, is sneaking around at night, showing up late to practice and jeopardizing their matches. Miri's boyfriend, Hamish, is too focused on his own game to notice. Then strange things begin interfering with Hamish's performance, and Kat suspects Miri may be involved. Who is trying to sabotage Hamish? And can Kat put a stop to the plot before it's too late?