Here's another .............................
You're flying into the circuit joining on base leg. Airfield info tells you there's traffic ahead on base, and traffic turning crosswind. You can't see the traffic ahead so look for the crosswind traffic and get a visual. You turn your attention back to the traffic ahead. You're at circuit height on the correct QFE and a little suprised you can't get a visual with the traffic ahead. You get a twitchy bum. You're approaching the point where you'd pull the power and start your descent. You pull yourself forward to get a better view and voila ........... The underside of another aircraft comencing a descent maybe 100ft above you.
What do you do ?