2008 Scion xB with a bad noise from the engine

My sister's xB died on the highway. I towed it to my house and was able to get it started, but heard this. I took it for a short drive and it is very noisey and WAY down on power. I think it's something wrong in the valvetrain/head, but I'm not very familiar with Toyota/Scion engines...yet. I have the feeling I'll be getting very familiar with them soon...