"What will have happened here by 6 o'clock tomorrow?" Mike wondered there by 6 o'clock the next day.

Для ответа на вопрос необходимо преобразовать прямую речь в косвенную в прошедшем времени.

Mike wondered what <strong>would have happened</strong> there by 6 o'clock the next day.

Ответ: would have happened