If your main time flag falls:
Count 10 stones from the bowl and make them visible to your opponent.
Close the bowl.
Referee resets the clock to 10 minutes.
Play all 10 stones before the flag falls.
When all your stones are finished, repeat the above steps.
When passing, give a stone to your opponent, then press the clock!
You must play the last of the 10 stones and press the clock before the flag falls. If the flag falls when you are in overtime, you lose.