Dr. Horrible's Sing-Along Blog was conceived by Joss Whedon during a Writers Guild of America strike. Whedon, who wanted to do something professional yet inexpensive, was able to round up a few actors — including Neil Patrick Harris (starring as a wannabe supervillain named Dr. Horrible), Nathan Fillion (as Dr. Horrible’s rival, Captain Hammer) and Felicia Day (as a mutual love interest of the two enemies) — for the musical mini web series. And voila! An Internet sensation was born. Local theater troupe Citizens of the Universe performs their own version of the tragi-comedy at The Chop Shop this week. For more information, visit www.citizensoftheuniverse.org.