You are right, this is a pretty improbable situation. But, I will give it a whack.
Aviate - Fly the plane. Fly it at as high of an altitude possible while still keeping visual contact with the ground. Just in case you lose an engine. Fly it in a wide circle or holding pattern until you get your bearings. Slow down your airspeed and lean your mixture for max endurance. You want to conserve fuel as well as ground position. No use in getting more lost quicker.
Navigate - Look for something identifiable. Or at least something that will lead you to civilization and suitable landing areas. Think of it like being lost on the ground. Look for your North direction using the sun or stars. Evaluate the ground for:
- High speed avenues of approach like roadways
- Key terrain features
- Man-made obstacles like towers or buildings
Find water. In the US water towers (not all) are marked with location names. If you find a river, you will usually find civilization close by. If you find a shoreline, you may be able to find a flat area suitable for landing.
Fly downhill. Fly towards the lowering terrain. You are more likely to find a landing area.
If all else fails go IFR (I Fly Roads).
Communicate - If the transponder works, squawk 7600. If you have a cell phone, try it. You May have to descend to get it to work. Only do so if you have established where you are and if the aircraft is safe to continue flight. Turn on all of your exterior lights. If you see an airport, circle directly above the field at 2000 to 4000 feet AGL and look for light gun signals.
Land as far away from the kidnappers/highjackers as possible.