Matt and Caroline are surprised by the sudden reappearance of Matt's estranged mother Kelly who arrives back in Mystic Falls with an agenda. Stefan and Elena are worried about Damon's new attitude, while one vampire from the crypt is loose and killing. Meanwhile, Damon is asked by Sheriff Forbes to take part in a fund-raising bachelor auction. Elsewhere, Alaric discovers shocking secrets from his own past over his late wife. With help from Jenna and Stefan, Elena is determined to find out everything she can about her birth mother, but the truth may be more than she can handle when she learns about Isobel's past, her gruesome demise... and her connection to Alaric.