missing belt

I purchased a 1997 Ford Contour with a V6 engine and found that there is a missing belt on on the upper left side of the engine. The engine runs pretty bad and I have no idea what this missing belt was supposed to do.

theres only two belts that are on the V6. On the passenger side is the main accessory belt which drives the AC condensor, power steering, alternator, etc. The other is on the drivers side which is a small belt which connects to the camshaft and helps spin the waterpump.