From your photo, hard to tell if it's there. You say it's a dual point, right?
Pull the cap off the distributor, and look at the points. Each should have a wire coming off of them, that goes to a screw head. Threads of that screw go 'outwards' of the housing, tightened down with a nut, with a number of threads left.
IF it is a dual point, of course you'll have two sets of points. But, you'll also have the condenser that mounts on the outside of the housing, near that screw's threads.
Back to that screw...wire lead from the condenser goes to that screw...also a lone separate wire...that goes to the coil. (That's the wire your missing, if nothing else.)
Last note...that screw again...should be a plastic insulator that fits in the housing, and keeps the screw from 'grounding' against the housing. If it grounds...no sparky!