It was about to speak, when the cock crew.
Act I, Scene 1
Context
Barnardo comments on the Ghost's abrupt departure, noting that it seemed ready to speak but vanished the moment the rooster crowed at dawn.
Analysis
The timing described here—'when the cock crew'—places the cock's crow as the direct cause of the Ghost's silence, giving the bird's natural behavior a kind of power over the supernatural. The line's matter-of-fact tone, almost like a stage direction, contrasts with the strangeness of what it reports: that a farmyard animal can banish a ghost. This juxtaposition of the mundane and the eerie runs throughout the scene.
Essay Tip
Use this to argue that Shakespeare gives everyday natural rhythms (dawn, crowing) authority over the Ghost, suggesting that the supernatural in this play is not all-powerful but constrained by ordinary time and creation.