Sylar breaks into Company headquarters, killing Bob Bishop and acquiring his power. He is captured after attempting to take Elle's power, which results in her involuntarily releasing an electric burst which knocks him unconscious. The discharge also disables the Level 5 security system, allowing a dozen dangerous inmates to escape the complex. Before Sylar can regain consciousness, he is locked up. During his imprisonment, Angela Petrelli claims that she is his mother and attempts to rehabilitate him. She allows him to kill Bridget Bailey, a woman who can see the history of an object by touching it, in order to feed his hunger for power. When Noah Bennet returns to the Company to hunt down the escaped villains, Angela assigns Sylar as his partner, sending the two out to confront the villains and save the trapped Peter Petrelli.
Source: Wikipedia