That coil will fire two plugs at a time, one on the compression stroke with fuel in the cylinder, and the other on the overlap position with nothing but exhaust gas in the head. It's called a "waste spark" system. Both plugs connected to that coil should be misfiring if there's an ignition-related problem. If only one cylinder is involved, you must have an open or a short in the wire going to that plug. That's assuming you've got fuel and compression to the cylinder that's missing. Swap both the plug and the wire to the bad cylinder, even if they're supposed to be "new".
Jerry
