The episode starts with Hiro and Claire at the deveaux rooftop where Bennet accepted baby Claire as a company assignment. Hiro read in the comic that he and Claire need to prevent baby Claire becoming the catalyst.
We see Ishi and Kaito talk about using baby Claire as the catalyst which is now in Ishi who is very ill. When young Hiro sees a pigeon who is almost dead in a cage he asks his mother to heal it.
In the present dat we see Sylar getting a call from Arthur. In this conversation Sylar is telling Arthur that he wants to now the truth and that he is operating by himself from now when the name Sue Landers shows up. The scene continues with Sylar burning Elle's body.
Peter and The Haitian are going to try and stop Arthur because Nathan has gone native. Peter and The Haitian are the only ones who can stop Arthur now.
In the next scene we see Nathan joining with Arthur and supporting his plan for use of synthetic abilities. Claire meets Sandra in the past and helps with taking care of little Claire. In the next scene Sylar is visiting Sue Landers to take here power which is 'Human Lie Detection'. Daphne, Matt and Ando get their hands on Isaac's Sketchbook. Hiro gets his memory healed by his mother and becomes the catalyst. When he and Claire try to leave Arthur shows op and absorbs Hiro's power and the light, Arthur now becomes the new catalyst. Arthur sends Claire back and pushes hero of the rooftop
Sylar now has the ability to detect lies and confronts Arthur when he meets Peter and The Haitian, Peter fires the gun. Sylar stops the buleet claiming Peter is not a killer, and he kills Arthur which already used the light to make synthetic abilities.
Scott, the test subject now has the synthetic ability of 'Enchaned Strength'.