What song did Alkaline Trio play in the studio on The Hills?

I spent all yesterday trying to find out "Why" and I honestly couldn't find a real reason for them to guest star on such a crap show. I guess it's because they are know signed to Epic records and they are making them into "Superstars" like Good Charlotte. The song was "In Vein" one of the three songs on the early release of their July 1st album.