The speaker watches someone being attacked: fists to the face, a head slammed against a wall. At first they just stand there, frozen. Then fear takes over their body and they run, so fast they can't even feel their feet. The detail makes the escape sound almost out of their control, as if the body decided before the mind could.
The second half is about what comes after. The short, broken lines ("Is he alive? / Why did I leave him?") read like panicked thoughts that keep circling. The speaker is haunted by guilt and by not knowing what happened. The poem ends on a blunt line, "Fear is the answer," which works as both an explanation and a confession. It doesn't excuse the running, but it admits the truth. The mood is tense, shaky and ashamed, with the speaker caught between self-protection and regret. The poem doesn't tell us who "he" is or whether he survived, which leaves the reader sitting in that same uncertainty.