Blackbird...is a distressing two-hander about the dangerous influence and magnetism of traumatic events. It courts ethical dangers, in daring to characterize the bond between abuser and abused as a kind of perverse love story...Under Joe Mantello's direction, there is considerable tension in the opening moments, not all of it calculated or purposeful. Daniels begins the play in such a paroxysm of fear and anger that one worries he will quickly exhaust himself...In Una's self-conscious performativity, Williams indicates an emotionally stunted young woman whose earlier ordeal has prevented her from ever establishing a coherent adult identity. As the play continues, she begins to exhibit a strong dissociative quality, showing the confusion she still experiences, the crossed wires of pain and desire...There are no weapons on display here...but this is the most lacerating play on Broadway this season.