Second word of fairy tales

• "It is incumbent ___ us to ..."
• Double preposition
• "Once ___ . . . "
• Stratford-___-Avon
• "___ the Roof" (1962-63 hit for the Drifters)
• At a prescribed point in time
• 'Oncea time ...'
• Follower of 54 Down
• "Climb ___ my knee . . . "

Wikipedia Word definitions in Wikipedia