Bart Allen is a teenage speedster and a member of the Flash Family who has gone by several code names. He was born in the 30th Century, the grandson of time-traveling speedster the Flash, although he returned to the past to continue his family's legacy. Because of his strange origins, he ages at an inconsistent rate. Originally, he took the name Impulse to reflect his impulsive nature. There was a brief period when he became The Flash after Infinite Crisis, but he was killed by the Rogues during Full Throttle. Later on, he was resurrected during Final Crisis through his connection to the Speed Force.

In the present he helps Flash and Kid Flash battle an unknown villain who is Bart's ally from the future. After being defeated Neutron starts to self destruct so Flash tries to carry him to the desert to minimize the damage but is tripped by Impulse. The two are saved by Kid Flash and Jay Garrick who take them out of the explosion range. Kid Flash is angry at Impulse until Flash reveals that he saved his life, as the fluctuation of the explosion increased and he would have died before he could get away after dropping Neutron off in the desert. Impulse uses a blue orb given to him by Neutron of the future to cure Neutron. He then pretends like he didn't know his time machine broke during the journey and stays in Central City with Jay Garrick.