"If you want to go back, I won't blame you,' he said. 'You can take the cloak, I won't need it now."
"Don't be stupid," said Ron.
"We're coming," said Hermione. (16.148-50).
Once again bravery is act first, think later, as Harry tries to persuade his friends to turn around and let him go forward alone; as Ron tells him, that's "stupid." In a way, it is foolhardy of all of them to continue, as their bravery puts all their lives in danger.