At Sundance 2014, filmmaker Jeff Baena, who co-wrote "I Heart Huckabees"  alongside David O'Russell, talks "Life After Beth." A zombie love story, the film stars Dane DeHaan as Zach, a young man who re-unites with his dead girlfriend Beth (Aubrey Plaza). Unfortunately, she's been resurrected as a zombie. Her mom and dad, played hilariously by Molly Shannon and John C. Reilly, refuse to accept her condition. Zach's brother Kyle (Matthew Gray Gubler) and parents (Paul Reiser and Cheryl Hines) don't believe his story until a complete zombie invasion ensues. Baena and his amazing cast talk grounding the comedy in truth, the great script and the underwear scene…