Throughout the first episode of Jessica Jones, Jessica (Krysten Ritter) works to find and help a missing girl.
It's eventually revealed that the girl has been under the influence of mind control by Kilgrave (David Tennant). And at the end of the episode, the control is used to force the girl to kill her own parents. Jessica realizes this too late.
While Jessica tries to stop it...she can't.
And when she sees the carnage she is overwhelmed — and pretty understandably completely freaked out.
Her first instinct is to get as far away as possible. She stumbles into the street, towards a cab...
But she pauses.
She contemplates her options.
She steels herself.
And then she goes back to help however she can.
It just goes to show what heroism means for Jessica Jones: You can't always fix things outright. And you might be completely freaked out. But an integral part of being the hero is the decision to show the fuck up even in spite of that.